ORCID Profile
0000-0001-9284-4929
Current Organisation
University of Queensland Institute for Molecular Bioscience
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Biochemistry and Cell Biology | Plant Biology | Structural Biology (incl. Macromolecular Modelling) | Industrial Biotechnology | Environmental Technologies | Systems Biology | Membrane Biology | Plant Cell and Molecular Biology | Gene Expression | Receptors and Membrane Biology | Synthetic Biology | Biophysics | Agricultural Biotechnology | Cell Metabolism | Enzymes | Genetic Engineering And Enzyme Technology | Industrial Microbiology (incl. Biofeedstocks) | Structural Chemistry | Biochemistry And Cell Biology Not Elsewhere Classified | Microbiology | Characterisation Of Macromolecules | Artificial Intelligence and Image Processing | Biochemistry and Cell Biology not elsewhere classified | Information Storage, Retrieval And Management | Biological Sciences Not Elsewhere Classified | Economic Models and Forecasting | Bacteriology | Applied Economics | Protein Targeting And Signal Transduction | Other Industrial Biotechnology | Fermentation, Biotechnology And Industrial Microbiology | Engineering Systems Design | Bioinorganic Chemistry | Inorganic Chemistry | Global Change Biology | Biotechnology Not Elsewhere Classified | Environmental Technologies | Agricultural Biotechnology not elsewhere classified | Aquaculture | Cellular Interactions (incl. Adhesion, Matrix, Cell Wall) | Agricultural Economics | Enzymes | Image Processing | Macromolecular and Materials Chemistry not elsewhere classified | Sustainable Agricultural Development | Phycology | Agricultural Production Systems Simulation | Biocatalysis and Enzyme Technology | Bioprocessing, Bioproduction and Bioproducts | Industrial Molecular Engineering of Nucleic Acids and Proteins
Biological sciences | Renewable energy not elsewhere classified (e.g. geothermal) | Plant Production and Plant Primary Products not elsewhere classified | Climate Change Adaptation Measures | Renewable energy | Hydrogen Production from Renewable Energy | Biofuel (Biomass) Energy | Climate change | Infectious diseases | Expanding Knowledge in the Biological Sciences | Production of Biofuels (Biomass) | Climate Change Mitigation Strategies | Economic Growth | Organic Industrial Chemicals (excl. Resins, Rubber and Plastics) | Environmentally Sustainable Manufacturing not elsewhere classified | Chemical sciences | Physical sciences | Other | Aquaculture | Cancer and Related Disorders | Infectious Diseases | Environmentally Sustainable Plant Production not elsewhere classified | Energy storage and distribution | Higher education | Cancer and related disorders | Expanding Knowledge in the Medical and Health Sciences | Scientific instrumentation | Expanding Knowledge in the Chemical Sciences | Scientific Instruments | Human Pharmaceutical Products not elsewhere classified |
Publisher: Elsevier BV
Date: 09-2010
Publisher: Springer Science and Business Media LLC
Date: 03-2008
Publisher: MDPI AG
Date: 05-04-2017
DOI: 10.3390/EN10040467
Publisher: Wiley
Date: 13-12-2022
Abstract: By co‐culturing selected microalgae and heterotrophic microorganisms, the growth rate of microalgae can be improved even under atmospheric conditions with a low CO 2 concentration. However, the detailed mechanism of improvement of proliferative capacity by co‐culture has not been elucidated. In this study, we investigated changes in the proliferative capacity of the green alga Chlamydomonas reinhardtii by co‐culturing with Escherichia coli . In the co‐culture, the number of C. reinhardtii cells reached 2.22 × 10 10 cell/L on day 14 of culture. This was about 1.9 times the number of cells (1.16 × 10 10 cell/L) on day 14 compared to C. reinhardtii cells in monoculture. The starch content per cell in the co‐culture of C. reinhardtii and E. coli on the 14th day (2.09 × 10 −11 g/cell) was 1.3 times higher than that in the C. reinhardtii monoculture (1.59 × 10 −11 g/cell), and the starch content per culture medium improved 2.5 times with co‐cultivation. By analyzing the gene transcription profiles and key media components, we clarified that E. coli produced CO 2 from the organic carbon in the medium and the organic carbon produced by photosynthesis of C. reinhardtii , and this CO 2 likely enhanced the growth of C. reinhardtii . Consequently, E. coli plays a key role in promoting the growth of C. reinhardtii as well as the accumulation of starch which is a valuable intermediate for the production of a range of useful chemicals from CO 2 .
Publisher: Elsevier BV
Date: 08-2019
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 06-2018
Publisher: OMICS Publishing Group
Date: 2013
Publisher: BMJ
Date: 11-2021
DOI: 10.1136/BMJOPEN-2020-047875
Abstract: Gender Identity Development Services (GIDS) worldwide have experienced a significant increase in referrals in recent years. However, little is currently known about the experiences of the children and young people (CYP) and their families attending these services and the influences on their well-being. Most published qualitative studies have explored gender identity and gender questioning CYP from either a parental perspective or in an adolescent s le. Consequently, there is a need for research to explore the voices of younger children and adolescents who are referred to GIDS. This study aims to address current gaps in understanding of the experiences of CYP referred to the UK GIDS, specifically regarding the personal, familial, educational, and social contexts in which CYP and their parents/caregivers are navigating gender identity, social and physical transition, and the healthcare system. A prospective longitudinal qualitative study examining the experiences and well-being of CYP referred to the UK GIDS. A purposive s le of up to 40 families will be recruited. Families will be eligible for the study if the child or young person was aged 3–14 years at the time of referral to the GIDS. Semistructured interviews will be conducted with both the child/young person and their parents/caregivers. Analysis of anonymised interview transcripts will be interpretive and pluralistic, informed by both narrative and thematic approaches. This study forms part of a wider programme of research investigating longitudinal outcomes of gender identity in children (the LOGIC Study). The proposed study has been approved by the UK Health Research Authority and London–H stead Research Ethics Committee as application 19/LO/0857. The study findings will be published in peer-reviewed journals and presented at both conferences and stakeholder events.
Publisher: Springer Science and Business Media LLC
Date: 03-08-2018
DOI: 10.1038/S41598-018-29954-X
Abstract: Microalgae biotechnologies are rapidly developing into new commercial settings. Several high value products already exist on the market, and systems development is focused on cost reduction to open up future economic opportunities for food, fuel and freshwater production. Light is a key environmental driver for photosynthesis and optimising light capture is therefore critical for low cost, high efficiency systems. Here a novel high-throughput screen that simulates fluctuating light regimes in mass cultures is presented. The data was used to model photosynthetic efficiency (PE µ , mol photon −1 m 2 ) and chlorophyll fluorescence of two green algae, Chlamydomonas reinhardtii and Chlorella sp. Response surface methodology defined the effect of three key variables: density factor (D f , ‘culture density’), cycle time (t c , ‘mixing rate’), and maximum incident irradiance (I max ). Both species exhibited a large rise in PE µ with decreasing I max and a minimal effect of t c (between 3–20 s). However, the optimal D f of 0.4 for Chlamydomonas and 0.8 for Chlorella suggested strong preferences for dilute and dense cultures respectively. Chlorella had a two-fold higher optimised PE µ than Chlamydomonas , despite its higher light sensitivity. These results demonstrate species-specific light preferences within the green algae clade. Our high-throughput screen enables rapid strain selection and process optimisation.
Publisher: Wiley
Date: 03-1998
DOI: 10.1046/J.1432-1327.1998.2520268.X
Abstract: A dimeric photosystem II light-harvesting II super complex (PSII-LHCII SC), isolated by sucrose density gradient centrifugation, was previously structurally characterized [Boekema, E. J., Hankamer, B., Bald, D., Kruip, J., Nield, J., Boonstra, A. F., Barber, J. & Rögner, M. (1995) Proc. Natl Acad. Sci. USA 92, 175-179]. This PSII-LHCII SC bound the 33-kDa subunit of the oxygen-evolving complex (OEC), but lacked the 23-kDa and 17-kDa subunits of the OEC. Here the isolation procedure was modified by adding 1 M glycine betaine (1-carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt) to the sucrose gradient mixture. This procedure yielded PSII-LHCII SC that contained both the 33-kDa and the 23-kDa subunits and had twice the oxygen-evolving capacity of the super complexes lacking the 23-kDa polypeptide. Addition of CaCl2 to PSII-LHCII SC with the 23-kDa subunit attached did not increase the oxygen-evolution rate. This suggests that the 23-kDa subunit is bound in a functional manner and is present in significant amounts. Over 5000 particle projections extracted from electron microscope images of negatively stained PSII-LHCII SC, isolated in the presence and absence of glycine betaine, were analyzed using single-particle image-averaging techniques. Both the 23-kDa and 33-kDa subunits could be visualized in top-view and side-view projections. In the side view the 23-kDa subunit is seen to protrude 0.5-1 nm further than the 33-kDa subunit, giving the PSII particle a maximal height of 9.5 nm. Measured from the centres of the masses, the two 33-kDa subunits associated with the dimeric PSII-LHCII SC are separated by 6.3 nm. The corresponding distance between the two 23-kDa subunits is 8.8 nm.
Publisher: EMBO
Date: 14-08-2009
Publisher: Elsevier BV
Date: 1990
Publisher: Wiley
Date: 09-2008
Publisher: Royal Society of Chemistry
Date: 2002
Publisher: Elsevier BV
Date: 04-2012
DOI: 10.1016/J.TIBTECH.2011.11.003
Abstract: Microalgal production technologies are seen as increasingly attractive for bioenergy production to improve fuel security and reduce CO(2) emissions. Photosynthetically derived fuels are a renewable, potentially carbon-neutral and scalable alternative reserve. Microalgae have particular promise because they can be produced on non-arable land and utilize saline and wastewater streams. Furthermore, emerging microalgal technologies can be used to produce a range of products such as biofuels, protein-rich animal feeds, chemical feedstocks (e.g. bioplastic precursors) and higher-value products. This review focuses on the selection, breeding and engineering of microalgae for improved biomass and biofuel conversion efficiencies.
Publisher: Proceedings of the National Academy of Sciences
Date: 18-12-2004
Abstract: The vacuole-type ATPases (V-ATPases) exist in various intracellular compartments of eukaryotic cells to regulate physiological processes by controlling the acidic environment. The crystal structure of the subunit C of Thermus thermophilus V-ATPase, homologous to eukaryotic subunit d of V-ATPases, has been determined at 1.95-Å resolution and located into the holoenzyme complex structure obtained by single particle analysis as suggested by the results of subunit cross-linking experiments. The result shows that V-ATPase is substantially longer than the related F-type ATPase, due to the insertion of subunit C between the V 1 (soluble) and the V o (membrane bound) domains. Subunit C, attached to the V o domain, seems to have a socket like function in attaching the central-stalk subunits of the V 1 domain. This architecture seems essential for the reversible association/dissociation of the V 1 and the V o domains, unique for V-ATPase activity regulation.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Wiley
Date: 23-05-2007
DOI: 10.1111/J.1399-3054.2007.00924.X
Abstract: The development of clean borderless fuels is of vital importance to human and environmental health and global prosperity. Currently, fuels make up approximately 67% of the global energy market (total market = 15 TW year(-1)) (Hoffert et al. 1998). In contrast, global electricity demand accounts for only 33% (Hoffert et al. 1998). Yet, despite the importance of fuels, almost all CO(2) free energy production systems under development are designed to drive electricity generation (e.g. clean-coal technology, nuclear, photovoltaic, wind, geothermal, wave and hydroelectric). In contrast, and indeed almost uniquely, biofuels also target the much larger fuel market and so in the future will play an increasingly important role in maintaining energy security (Lal 2005). Currently, the main biofuels that are at varying stages of development include bio-ethanol, liquid carbohydrates [e.g. biodiesel or biomass to liquid (BTL) products], biomethane and bio-H(2). This review is focused on placing bio-H(2) production processes into the context of the current biofuels market and summarizing advances made both at the level of bioengineering and bioreactor design.
Publisher: Wiley
Date: 31-08-2007
DOI: 10.1111/J.1467-7652.2007.00285.X
Abstract: The main function of the photosynthetic process is to capture solar energy and to store it in the form of chemical 'fuels'. Increasingly, the photosynthetic machinery is being used for the production of biofuels such as bio-ethanol, biodiesel and bio-H2. Fuel production efficiency is directly dependent on the solar photon capture and conversion efficiency of the system. Green algae (e.g. Chlamydomonas reinhardtii) have evolved genetic strategies to assemble large light-harvesting antenna complexes (LHC) to maximize light capture under low-light conditions, with the downside that under high solar irradiance, most of the absorbed photons are wasted as fluorescence and heat to protect against photodamage. This limits the production process efficiency of mass culture. We applied RNAi technology to down-regulate the entire LHC gene family simultaneously to reduce energy losses by fluorescence and heat. The mutant Stm3LR3 had significantly reduced levels of LHCI and LHCII mRNAs and proteins while chlorophyll and pigment synthesis was functional. The grana were markedly less tightly stacked, consistent with the role of LHCII. Stm3LR3 also exhibited reduced levels of fluorescence, a higher photosynthetic quantum yield and a reduced sensitivity to photoinhibition, resulting in an increased efficiency of cell cultivation under elevated light conditions. Collectively, these properties offer three advantages in terms of algal bioreactor efficiency under natural high-light levels: (i) reduced fluorescence and LHC-dependent heat losses and thus increased photosynthetic efficiencies under high-light conditions (ii) improved light penetration properties and (iii) potentially reduced risk of oxidative photodamage of PSII.
Publisher: Springer Science and Business Media LLC
Date: 10-06-2010
DOI: 10.1007/S00253-010-2697-X
Abstract: The production of biofuels from microalgae requires efficient photobioreactors in order to meet the tight constraints of energy efficiency and economic profitability. Current cultivation systems are designed for high-value products rather than for mass production of cheap energy carriers. Future bioreactors will imply innovative solutions in terms of energy efficiency, light and gas transfer or attainable biomass concentration to lower the energy demand and cut down production costs. A new generation of highly developed reactor designs demonstrates the enormous potential of photobioreactors. However, a net energy production with microalgae remains challenging. Therefore, it is essential to review all aspects and production steps for optimization potential. This includes a custom process design according to production organism, desired product and production site. Moreover, the potential of microalgae to synthesize valuable products additionally to the energetic use can be integrated into a production concept as well as waste streams for carbon supply or temperature control.
Publisher: Elsevier BV
Date: 08-2009
Publisher: Portland Press Ltd.
Date: 19-06-2015
DOI: 10.1042/BJ20150217
Abstract: Light-harvesting complex (LHC) proteins are among the most abundant proteins on Earth and play critical roles in photosynthesis, both in light capture and in photoprotective mechanisms. The Chlamydomonas reinhardtii nucleic acid-binding protein 1 (NAB1) is a negative regulator of LHC protein translation. Its N-terminal cold-shock domain (CSD) binds to a 13-nt element [CSD consensus sequence (CSDCS)] found in the mRNA of specific LHC proteins associated with Photosystem II (PSII), an interaction which regulates LHC expression and, consequently, PSII-associated antenna size, structure and function. In the present study, we elucidated the solution structure of the NAB1 CSD as determined by heteronuclear NMR. The CSD adopts a characteristic five-stranded anti parallel β-barrel fold. Upon addition of CSDCS RNA, a large number of NMR chemical shift perturbations were observed, corresponding primarily to surface-exposed residues within the highly conserved β2- and β3-strands in the canonical RNA-binding region, but also to residues on β-strand 5 extending the positive surface patch and the overall RNA-binding site. Additional chemical shift perturbations that accompanied RNA binding involved buried residues, suggesting that transcript recognition is accompanied by conformational change. Our results indicate that NAB1 associates with RNA transcripts through a mechanism involving its CSD that is conserved with mechanisms of sequence-specific nucleic acid recognition employed by ancestrally related bacterial cold-shock proteins (CSPs).
Publisher: Public Library of Science (PLoS)
Date: 15-05-2014
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.TPLANTS.2019.06.005
Abstract: Photosynthetic microalgae are unicellular plants, many of which are rich in protein, lipids, and bioactives and form an important part of the base of the natural aquatic food chain. Population growth, demand for high-quality protein, and depletion of wild fishstocks are forecast to increase aquacultural fish demand by 37% between 2016 and 2030. This review highlights the role of microalgae and recent advances that can support a sustainable 'circular' aquaculture industry. Microalgae-based feed supplements and recombinant therapeutic production offer significant opportunities to improve animal health, disease resistance, and yields. Critically, microalgae in biofloc, 'green water', nutrient remediation, and integrated multitrophic aquaculture technologies offer innovative solutions for economic and environmentally sustainable development in line with key UN Sustainability Goals.
Publisher: Elsevier BV
Date: 12-2007
DOI: 10.1016/J.JSB.2007.07.002
Abstract: A defining property of a crystal is its symmetry. This mini-review sets out to summarize all aspects that define 2D crystallographic symmetry as applied to the study of macromolecular structure. It begins by defining molecular point symmetries, before covering crystallographic symmetry operations in 2D, common notation, a summary of crystallographic plane groups and theoretical methods and important considerations for the identification and application of symmetry in 2D crystal images for 3D structure determination. While many of the concepts covered here may be equally applicable to point symmetry and space group symmetry in 3D, this review has been written from the perspective of 2D electron crystallography and deals specifically with symmetry operations and crystallographic space groups in 2D crystal projection images.
Publisher: Springer International Publishing
Date: 2022
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.JMB.2011.11.018
Abstract: Yersinia entomophaga MH96 is a native New Zealand soil bacterium that secretes a large ABC-type protein toxin complex, Yen-Tc, similar to those produced by nematode-associated bacteria such as Photorhabdus luminescens. Y. entomophaga displays an exceptionally virulent pathogenic phenotype in sensitive insect species, causing death within 72 h of infection. Because of this phenotype, there is intrinsic interest in the mechanism of action of Yen-Tc, and it also has the potential to function as a novel class of biopesticide. We have identified genes that encode chitinases as part of the toxin complex loci in Y. entomophaga MH96, P. luminescens, Photorhabdus asymbiotica and Xenorhabdus nematophila. Furthermore, we have shown that the secreted toxin complex from Y. entomophaga MH96 includes two chitinases as an integral part of the complex, a feature not described previously in other ABC toxins and possibly related to the severe disease caused by this bacterium. We present here the structure of the Y. entomophaga MH96 Chi1 chitinase, determined by X-ray crystallography to 1.74 Å resolution, and show that a ring of five symmetrically arranged lobes on the surface of the Yen-Tc toxin complex structure, as determined by single-particle electron microscopy, provides a good fit to the Chi1 monomer. We also confirm that the isolated chitinases display endochitinase activity, as does the complete toxin complex.
Publisher: OMICS Publishing Group
Date: 2013
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 05-2023
Publisher: Elsevier BV
Date: 06-2011
Publisher: Proceedings of the National Academy of Sciences
Date: 03-01-1995
Abstract: Photosystem II (PSII) complexes, isolated from spinach and the thermophilic cyanobacterium Synechococcus elongatus, were characterized by electron microscopy and single-particle image-averaging analyses. Oxygen-evolving core complexes from spinach and Synechococcus having molecular masses of about 450 kDa and dimensions of approximately 17.2 x 9.7 nm showed twofold symmetry indicative of a dimeric organization. Confirmation of this came from image analysis of oxygen-evolving monomeric cores of PSII isolated from spinach and Synechococcus having a mass of approximately 240 kDa. Washing with Tris at pH 8.0 and analysis of side-view projections indicated the possible position of the 33-kDa extrinsic manganese-stabilizing protein. A larger complex was isolated that contained the light-harvesting complex II (LHC-II) and other chlorophyll a/b-binding proteins, CP29, CP26, and CP24. This LHC-II-PSII complex had a mass of about 700 kDa, and electron microscopy revealed it also to be a dimer having dimensions of about 26.8 and 12.3 nm. From comparison with the dimeric core complex, it was deduced that the latter is located in the center of the larger particle, with additional peripheral regions accommodating the chlorophyll a/b-binding proteins. It is suggested that two LHC-II trimers are present in each dimeric LHC-II-PSII complex and that each trimer is linked to the reaction center core complex by CP24, CP26, and CP29. The results also suggest that PSII may exist as a dimer in vivo.
Publisher: Springer Science and Business Media LLC
Date: 11-04-2015
Publisher: Oxford University Press (OUP)
Date: 08-2005
Publisher: Elsevier BV
Date: 03-2000
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9GC03120K
Abstract: Hydrothermal pre-treatment (HTP) allows microalgal protein extraction. Subsequent acetone and urea treatments improve the extraction efficiency.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Springer Science and Business Media LLC
Date: 10-1997
DOI: 10.1038/39103
Publisher: Mary Ann Liebert Inc
Date: 20-02-2014
Abstract: Sensations of touch and hearing are manifestations of mechanical contact and air pressure acting on touch receptors and hair cells of the inner ear, respectively. In bacteria, osmotic pressure exerts a significant mechanical force on their cellular membrane. Bacteria have evolved mechanosensitive (MS) channels to cope with excessive turgor pressure resulting from a hypo-osmotic shock. MS channel opening allows the expulsion of osmolytes and water, thereby restoring normal cellular turgor and preventing cell lysis. As biological force-sensing systems, MS channels have been identified as the best ex les of membrane proteins coupling molecular dynamics to cellular mechanics. The bacterial MS channel of large conductance (MscL) and MS channel of small conductance (MscS) have been subjected to extensive biophysical, biochemical, genetic, and structural analyses. These studies have established MscL and MscS as model systems for mechanosensory transduction. In recent years, MS ion channels in mammalian cells have moved into focus of mechanotransduction research, accompanied by an increased awareness of the role they may play in the pathophysiology of diseases, including cardiac hypertrophy, muscular dystrophy, or Xerocytosis. A recent exciting development includes the molecular identification of Piezo proteins, which function as nonselective cation channels in mechanosensory transduction associated with senses of touch and pain. Since research on Piezo channels is very young, applying lessons learned from studies of bacterial MS channels to establishing the mechanism by which the Piezo channels are mechanically activated remains one of the future challenges toward a better understanding of the role that MS channels play in mechanobiology.
Publisher: Springer Science and Business Media LLC
Date: 07-06-2021
DOI: 10.1186/S13068-021-01972-4
Abstract: Microalgae-based high-density fuels offer an efficient and environmental pathway towards decarbonization of the transport sector and could be produced as part of a globally distributed network without competing with food systems for arable land. Variations in climatic and economic conditions significantly impact the economic feasibility and productivity of such fuel systems, requiring harmonized technoeconomic assessments to identify important conditions required for commercial scale up. Here, our previously validated Techno-economic and Lifecycle Analysis (TELCA) platform was extended to provide a direct performance comparison of microalgae diesel production at 12 international locations with variable climatic and economic settings. For each location, historical weather data, and jurisdiction-specific policy and economic inputs were used to simulate algal productivity, evaporation rates, harvest regime, CapEx and OpEx, interest and tax under location-specific operational parameters optimized for Minimum Diesel Selling Price (MDSP, US$ L −1 ). The economic feasibility, production capacity and CO 2-eq emissions of a defined 500 ha algae-based diesel production facility is reported for each. Under a for-profit business model, 10 of the 12 locations achieved a minimum diesel selling price (MDSP) under US$ 1.85 L −1 / US$ 6.99 gal −1 . At a fixed theoretical MDSP of US$ 2 L −1 (US$ 7.57 gal −1 ) these locations could achieve a profitable Internal Rate of Return (IRR) of 9.5–22.1%. Under a public utility model (0% profit, 0% tax) eight locations delivered cost-competitive renewable diesel at an MDSP of US$ 1.24 L −1 (US$ 4.69 gal −1 ). The CO 2-eq emissions of microalgae diesel were about one-third of fossil-based diesel. The public utility approach could reduce the fuel price toward cost-competitiveness, providing a key step on the path to a profitable fully commercial renewable fuel industry by attracting the investment needed to advance technology and commercial biorefinery co-production options. Governments’ adoption of such an approach could accelerate decarbonization, improve fuel security, and help support a local COVID-19 economic recovery. This study highlights the benefits and limitations of different factors at each location (e.g., climate, labour costs, policy, C-credits) in terms of the development of the technology—providing insights on how governments, investors and industry can drive the technology forward.
Publisher: Elsevier BV
Date: 06-1997
DOI: 10.1016/S0969-2126(97)00237-2
Abstract: Photosystem II (PSII) is a multisubunit protein complex which is embedded in the photosynthetic membranes of plants. It uses light energy to split water into molecular oxygen and reducing equivalents. PSII can be isolated with varying degrees of complexity in terms of its subunit composition and activity. To date, no three-dimensional (3-D) structure of the PSII complex has been determined which allows location of the proteins within the PSII complex and their orientation in relation to the thylakoid membrane. Two-dimensional (2-D) PSII core complex crystals composed of the two reaction centre proteins, D1 and D2, two chlorophyll-binding proteins, CP47 and CP43, cytb559 and associated low molecular weight proteins were formed after reconstituting the isolated complex into purified thylakoid lipids. Electron micrographs of negatively stained crystals were used for 2-D and 3-D image analyses. In the resulting maps, the PSII complex is composed of two halves related by twofold rotational symmetry, thus, confirming the dimeric nature of the complex each monomer appears to contain five domains. Comparison of the 3-D images with platinum shadowed images of the crystals allowed the likely lumenal and stromal surfaces of the complex to be identified and regions contained within the membrane to be inferred. The projection structure of 2-D crystals of a smaller CP47-D1-D2-cytb559 complex was used to identify the domains apparently associated with CP43. The results indicate that PSII probably exists as a dimer in vivo. The extensive proteinaceous protrusions from the lumenal surface have been tentatively assigned to hydrophilic loops of CP47 and CP43 the positioning of these loops possibly implies their involvement in the water-splitting process.
Publisher: Springer Science and Business Media LLC
Date: 05-08-2006
DOI: 10.1007/S00253-006-0528-X
Abstract: The rapid development of clean fuels for the future is a critically important global challenge for two main reasons. First, new fuels are needed to supplement and ultimately replace depleting oil reserves. Second, fuels capable of zero CO2 emissions are needed to slow the impact of global warming. This review summarizes the development of solar powered bio-H2 production processes based on the conversion of photosynthetic products by fermentative bacteria, as well as using photoheterotrophic and photoautrophic organisms. The use of advanced bioreactor systems and their potential and limitations in terms of process design, efficiency, and cost are also briefly reviewed.
Publisher: American Society for Microbiology
Date: 08-2008
DOI: 10.1128/JVI.00764-08
Abstract: A three-dimensional (3D) cryoelectron microscopy reconstruction of the prototype Atadenovirus (OAdV [an ovine adenovirus isolate]) showing information at a 10.6-Å resolution (0.5 Fourier shell correlation) was derived by single-particle analysis. This is the first 3D structure solved for any adenovirus that is not a Mastadenovirus , allowing cross-genus comparisons between structures and the assignment of genus-specific capsid proteins. Viable OAdV mutants that lacked the genus-specific LH3 and p32k proteins in purified virions were also generated. Negatively stained 3D reconstructions of these mutants were used to identify the location of protein LH3 and infer that of p32k within the capsid. The key finding was that LH3 is a critical protein that holds the outer capsid of the virus together. In its absence, the outer viral capsid is unstable. LH3 is located in the same position among the hexon subunits as its protein IX equivalent from mastadenoviruses but sits on top of the hexon trimers, forming prominent “knobs” on the virion surface that visually distinguish OAdV from other known AdVs. Electron density was also assigned to hexon and penton subunits and to proteins IIIa and VIII. There was good correspondence between OAdV density and human AdV hexon structures, which also validated the significant differences that were observed between the penton base protein structures.
Publisher: Public Library of Science (PLoS)
Date: 09-03-2016
Publisher: Wiley
Date: 1997
DOI: 10.1111/J.1432-1033.1997.0422A.X
Abstract: Membranes enriched in photosystem II were isolated from spinach and further solubilised using n ‐octyl β‐ d ‐glucopyranoside (OctGlc) and n ‐dodecyl β‐ d ‐maltoside (DodCl 2 ). The OctGlc preparation had high rates of oxygen evolution and when subjected to size‐exclusion HPLC and sucrose density gradient centrifugation, in the presence of DodGlc 2 , separated into dimeric (430 kDa), monomeric (236 kDa) photosystem II cores and a fraction containing photosystem II light‐harvesting complex (Lhcb) proteins. The dimeric core fraction was more stable, contained higher levels of chlorophyll, β‐carotene and plastoquinone per photosystem II reaction centre and had a higher oxygen‐evolving activity than the monomeric cores. Their subunit composition was similar (CP43, CP47, DI, D2, cytochrome b 559 and several lower‐molecular‐mass components) except that the level of 33‐kDa extrinsic protein was lower in the monomeric fraction. Direct solubilisation of photosystem‐II‐enriched membranes with DodGlc 2 , followed by sucrose density gradient centrifugation, yielded a super complex (700 kDa) containing the dimeric form of the photosystem II core and Lhcb proteins: Lhcbl, Lhcb2, Lhcb4 (CP29), and LhcbS (CP26). Like the dimeric and monomeric photosystem II core complexes, the photosystem II‐LHCII complex had lost the 23‐kDa and 17‐kDa extrinsic proteins, but maintained the 33‐kDa protein and the ability to evolve oxygen. It is suggested. with a proposed model, that the isolated photosystem II‐LHCII super complex represents an in vivo organisation that can sometimes form a lattice in granal membranes of the type detected by freeze‐etch electron microscopy [Seibert, M., DeWit, M. & Staehelin, L. A. (1987) J. Cell Biol. 105 , 2257–22651.
Publisher: Elsevier BV
Date: 09-2015
Publisher: DE GRUYTER
Date: 12-12-2012
Publisher: Springer Netherlands
Date: 2005
Publisher: Proceedings of the National Academy of Sciences
Date: 07-12-2011
Abstract: Toxin complex (Tc) proteins are a class of bacterial protein toxins that form large, multisubunit complexes. Comprising TcA, B, and C components, they are of great interest because many exhibit potent insecticidal activity. Here we report the structure of a novel Tc, Yen-Tc, isolated from the bacterium Yersinia entomophaga MH96, which differs from the majority of bacterially derived Tcs in that it exhibits oral activity toward a broad range of insect pests, including the diamondback moth ( Plutella xylostella ). We have determined the structure of the Yen-Tc using single particle electron microscopy and studied its mechanism of toxicity by comparative analyses of two variants of the complex exhibiting different toxicity profiles. We show that the A subunits form the basis of a fivefold symmetric assembly that differs substantially in structure and subunit arrangement from its most well characterized homologue, the Xenorhabdus nematophila toxin XptA1. Histopathological and quantitative dose response analyses identify the B and C subunits, which map to a single, surface-accessible region of the structure, as the sole determinants of toxicity. Finally, we show that the assembled Yen-Tc has endochitinase activity and attribute this to putative chitinase subunits that decorate the surface of the TcA scaffold, an observation that may explain the oral toxicity associated with the complex.
Publisher: Public Library of Science (PLoS)
Date: 11-11-2013
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.TPLANTS.2018.11.010
Abstract: The rapid accumulation of plastic waste is driving international demand for renewable plastics with superior qualities (e.g., full biodegradability to CO
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 04-2016
Publisher: Public Library of Science (PLoS)
Date: 2011
Publisher: Elsevier BV
Date: 07-2007
DOI: 10.1016/J.JSB.2007.03.003
Abstract: The automation of single particle selection and tomographic segmentation of asymmetric particles and objects is facilitated by continuing improvement of methods based on the detection of pixel discontinuity. Here, we present the new arbitrary z-crossings approach which can be employed to enhance the accuracy of edge detection algorithms that are based on the second derivative. This is demonstrated using the Laplacian of Gaussian (LoG) filter. In its normal implementation the LoG filter uses a z value of zero to define edge contours. In contrast, the arbitrary z-crossings approach allows the user to adjust z, which causes the subsequently generated contours to tend towards lighter or darker image objects, depending on the sign of z. This functionality has been coupled with an additional feature: the ability to use the major and minor axes of bounding contours to hone automated object selection. In combination, these features significantly enhance the accuracy of particle selection and the speed of tomographic segmentation. Both features have been incorporated into the software package Swarm(PS) in which parameters are automatically adjusted based on user defined target selection.
Publisher: Public Library of Science (PLoS)
Date: 2011
Publisher: Springer Science and Business Media LLC
Date: 05-07-2015
DOI: 10.1007/S00249-015-1055-4
Abstract: The mechanosensitive channel of large conductance (MscL) from Escherichia coli is a prototype for the mechanosensitive class of ion channels and opens one of the largest known gated transmembrane pores. As such, MscL offers the structural framework for the development of liposomal nanovalves for biotechnological applications. Here we incorporated MscL into liposomes and investigated the effects of L-α-lysophosphatidylcholine (LPC) with varying acyl chain lengths or saturation on its pore gating. This was measured by the efflux of encapsulated 5,6-carboxyfluorescein (CF) from the MscL proteoliposomes. Efflux improved in the presence of shorter and double-bonded LPC acyl chains. It was also dependent on the detergent concentration employed during MscL purification. MscL purified in 2 mM dodecyl β-D-maltopyranoside (DDM) had a marked increase in CF efflux compared to MscL purified in 1 mM DDM when treated with LPC. The purification conditions also resulted in increased efflux from proteoliposomes containing the G22C-MscL pore mutant channel, which requires higher membrane tension for its activation compared to WT-MscL.
Publisher: Elsevier BV
Date: 2016
Publisher: Wiley
Date: 16-08-2001
DOI: 10.1016/S0014-5793(01)02766-1
Abstract: Recently 3D structural models of the photosystem II (PSII) core dimer complexes of higher plants (spinach) and cyanobacteria (Synechococcus elongatus) have been derived by electron [Rhee et al. (1998) Nature 396, 283-286 Hankamer et al. (2001) J. Struct. Biol., in press] and X-ray [Zouni et al. (2001) Nature 409, 739-743] crystallography respectively. The intermediate resolutions of these structures do not allow direct identification of side chains and therefore many of the in idual subunits within the structure are unassigned. Here we review the structure of the higher plant PSII core dimer and provide evidence for the tentative assignment of the low molecular weight subunits. In so doing we highlight the similarities and differences between the higher plant and cyanobacterial structures.
Publisher: Annual Reviews
Date: 06-1997
DOI: 10.1146/ANNUREV.ARPLANT.48.1.641
Abstract: ▪ Abstract Photosystem II (PSII) is the pigment protein complex embedded in the thylakoid membrane of higher plants, algae, and cyanobacteria that uses solar energy to drive the photosynthetic water-splitting reaction. This chapter reviews the primary, secondary, tertiary, and quaternary structures of PSII as well as the function of its constituent subunits. The understanding of in vivo organization of PSII is based in part on freeze-etched and freeze-fracture images of thylakoid membranes. These images show a resolution of about 40–50 Å and so provide information mainly on the localization, heterogeneity, dimensions, and shapes of membrane-embedded PSII complexes. Higher resolution of about 15–40 Å has been obtained from single particle images of isolated PSII complexes of defined and differing subunit composition and from electron crystallography of 2-D crystals. Observations are discussed in terms of the oligomeric state and subunit organization of PSII and its antenna components.
Publisher: Oxford University Press (OUP)
Date: 04-2009
DOI: 10.1093/JXB/ERP052
Publisher: Elsevier BV
Date: 08-2021
Publisher: Worldwide Protein Data Bank
Date: 13-01-2004
DOI: 10.2210/PDB1R5Z/PDB
Publisher: Wiley
Date: 14-08-2014
Publisher: Oxford University Press (OUP)
Date: 08-2007
Publisher: Wiley
Date: 11-02-2008
DOI: 10.1111/J.1742-4658.2008.06300.X
Abstract: Sorting of membrane proteins into intralumenal endosomal vesicles, multivesicular body (MVB) sorting, is critical for receptor down regulation, antigen presentation and enveloped virus budding. Vps4 is an AAA ATPase that functions in MVB sorting. Although AAA ATPases are oligomeric, mechanisms that govern Vps4 oligomerization and activity remain elusive. Vps4 has an N‐terminal microtubule interacting and trafficking domain required for endosome recruitment, an AAA domain containing the ATPase catalytic site and a β domain, and a C‐terminal α helix positioned close to the catalytic site in the 3D structure. Previous attempts to identify the role of the C‐terminal helix have been unsuccessful. Here, we show that the C‐terminal helix is important for Vps4 assembly and ATPase activity in vitro and function in vivo , but not endosome recruitment or interactions with Vta1 or ESCRT‐III. Unlike the β domain, which is also important for Vps4 assembly, the C‐terminal helix is not required in vivo for Vps4 homotypic interaction or dominant‐negative effects of Vps4–E233Q, carrying a mutation in the ATP hydrolysis site. Vta1 promotes assembly of hybrid complexes comprising Vps4–E233Q and Vps4 lacking an intact C‐terminal helix in vitro . Formation of catalytically active hybrid complexes demonstrates an intersubunit catalytic mechanism for Vps4. One end of the C‐terminal helix lies in close proximity to the second region of homology (SRH), which is important for assembly and intersubunit catalysis in AAA ATPases. We propose that Vps4 SRH function requires an intact C‐terminal helix. Co‐evolution of a distinct Vps4 SRH and C‐terminal helix in meiotic clade AAA ATPases supports this possibility.
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.JSB.2017.10.002
Abstract: Resolving the 3D architecture of cells to atomic resolution is one of the most ambitious challenges of cellular and structural biology. Central to this process is the ability to automate tomogram segmentation to identify sub-cellular components, facilitate molecular docking and annotate detected objects with associated metadata. Here we demonstrate that RAZA (Rapid 3D z-crossings algorithm) provides a robust, accurate, intuitive, fast, and generally applicable segmentation algorithm capable of detecting organelles, membranes, macromolecular assemblies and extrinsic membrane protein domains. RAZA defines each continuous contour within a tomogram as a discrete object and extracts a set of 3D structural fingerprints (major, middle and minor axes, surface area and volume), enabling selective, semi-automated segmentation and object extraction. RAZA takes advantage of the fact that the underlying algorithm is a true 3D edge detector, allowing the axes of a detected object to be defined, independent of its random orientation within a cellular tomogram. The selectivity of object segmentation and extraction can be controlled by specifying a user-defined detection tolerance threshold for each fingerprint parameter, within which segmented objects must fall and/or by altering the number of search parameters, to define morphologically similar structures. We demonstrate the capability of RAZA to selectively extract subgroups of organelles (mitochondria) and macromolecular assemblies (ribosomes) from cellular tomograms. Furthermore, the ability of RAZA to define objects and their contours, provides a basis for molecular docking and rapid tomogram annotation.
Publisher: Elsevier BV
Date: 10-2005
Publisher: Bentham Science Publishers Ltd.
Date: 09-2009
Publisher: Elsevier BV
Date: 2016
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.TPLANTS.2022.03.001
Abstract: Using synthetic biology, it is now time to expand the biosynthetic repertoire of plants and microalgae by utilizing the chloroplast to augment the production of desired high-value compounds and of oil-, carbohydrate-, or protein-enriched biomass based on direct harvesting of solar energy and the consumption of CO
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 07-2022
Publisher: Elsevier BV
Date: 12-2009
Publisher: Wiley
Date: 25-04-2013
DOI: 10.1002/BBB.1404
Publisher: Springer Science and Business Media LLC
Date: 02-08-2015
DOI: 10.1007/S00249-015-1062-5
Abstract: The mechanosensitive channel of large conductance MscL is a well-characterized mechanically gated non-selective ion channel, which often serves as a prototype mechanosensitive channel for mechanotransduction studies. However, there are some discrepancies between MscL constructs used in these studies, most notably unintended heterogeneous expression from some MscL expression constructs. In this study we investigate the possible cause of this expression pattern, and compare the original non-homogenously expressing constructs with our new homogeneously expressing one to confirm that there is little functional difference between them. In addition, a new MscL construct has been developed with an improved molar extinction coefficient at 280 nm, enabling more accurate protein quantification.
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 03-2004
Publisher: Elsevier BV
Date: 02-2020
Publisher: Elsevier BV
Date: 09-2021
Publisher: Wiley
Date: 23-01-2015
DOI: 10.1111/PBI.12516
Publisher: Public Library of Science (PLoS)
Date: 29-12-2011
Publisher: Microbiology Society
Date: 04-2012
Abstract: The flavivirus non-structural protein 1 (NS1) is a glycoprotein that is secreted as a soluble hexameric complex during the course of natural infection. Growing evidence indicates that this secreted form of NS1 (sNS1) plays a significant role in immune evasion and modulation during infection. Attempts to determine the crystal structure of NS1 have been unsuccessful to date and relatively little is known about the macromolecular organization of the sNS1 hexamer. Here, we have applied single-particle analysis to images of baculovirus-derived recombinant dengue 2 virus NS1 obtained by electron microscopy to determine its 3D structure to a resolution of 23 Å. This structure reveals a barrel-like organization of the three dimeric units that comprise the hexamer and provides further insights into the overall organization of oligomeric sNS1.
Publisher: Public Library of Science (PLoS)
Date: 11-02-2014
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3EE40534F
Publisher: MDPI AG
Date: 25-10-2022
Abstract: LOGiC-Q is a prospective longitudinal qualitative study that explores the experiences of children and young people, and their families, who have been referred to the Gender Identity Development Service (GIDS) in the UK. This paper describes the experiences of children and young people and their parents while they are on the waiting list to be seen. Semi-structured interviews were undertaken with 39 families who had been referred to GIDS and were waiting for their first appointment with the service. Both parent and child/young person were interviewed. Analysis of the anonymised interview transcripts was informed by both narrative and thematic approaches, and three predominant narratives around waiting were identified: 1. Positive experiences attached to waiting 2. Feelings of distress and stuckness 3. Suggestions for support while waiting. Findings from this study indicate variations in how waiting is experienced depending on the age of the child, and how distressed their body makes them feel. Young people and their parents offered suggestions for how the service could support families on the waiting list. These suggestions related primarily to ways of checking in and providing reassurance that they were at least still on the list as well as ideas about how to make the wait less distressing, rather than necessarily making the wait shorter, which was more spoken about in terms of an ideal rather than a realistic option.
Publisher: Elsevier BV
Date: 07-2023
Publisher: Elsevier BV
Date: 06-2010
DOI: 10.1016/J.COPBIO.2010.03.012
Abstract: A select group of unicellular green algae have evolved the ability to capture solar energy and to use it to split water to produce molecular oxygen (released into the atmosphere) as well as H(+) and e(-) that are combined to produce hydrogen. Theoretically this process therefore forms the basis for the development of sustainable solar powered hydrogen fuel production systems. This article reviews recent advances made and highlights key areas for further development as part of a strategy of establishing economically viable hydrogen production systems.
Publisher: Springer Science and Business Media LLC
Date: 26-04-2019
DOI: 10.1038/S41467-019-09890-8
Abstract: ABC toxins are pore-forming virulence factors produced by pathogenic bacteria. YenTcA is the pore-forming and membrane binding A subunit of the ABC toxin YenTc, produced by the insect pathogen Yersinia entomophaga . Here we present cryo-EM structures of YenTcA, purified from the native source. The soluble pre-pore structure, determined at an average resolution of 4.4 Å, reveals a pentameric assembly that in contrast to other characterised ABC toxins is formed by two TcA-like proteins (YenA1 and YenA2) and decorated by two endochitinases (Chi1 and Chi2). We also identify conformational changes that accompany membrane pore formation by visualising YenTcA inserted into liposomes. A clear outward rotation of the Chi1 subunits allows for access of the protruding translocation pore to the membrane. Our results highlight structural and functional ersity within the ABC toxin subfamily, explaining how different ABC toxins are capable of recognising erse hosts.
Publisher: Public Library of Science (PLoS)
Date: 16-04-2013
Publisher: American Chemical Society (ACS)
Date: 14-01-2009
DOI: 10.1021/JO802651P
Abstract: Nickel-chelating lipids have been synthesized for use as functionalized templates for 2-D crystallization of membrane proteins. These monolayer-forming lipids have been designed with three distinct components: (i) a branched hydrocarbon tail to confer fluidity of the monolayer, (ii) a perfluorinated central core for detergent resistance, and (iii) a nickel-chelating hydrophilic headgroup to facilitate binding of recombinant, polyhistidine-tagged fusion proteins. Alkylations of fluorinated alcohols used in these syntheses proceed in good yields only with the application of prolonged sonication and, in some cases, in the presence of phase-transfer catalysts. Formation of 2-D crystals of the His-tagged membrane protein BmrA from Bacillus subtilis is reported.
Publisher: Elsevier BV
Date: 06-2009
DOI: 10.1016/J.JBIOTEC.2009.02.015
Abstract: The efficient use of microalgae to convert sun light energy into biomass is limited by losses during high light illumination of dense cell cultures in closed bioreactors. Uneven light distribution can be overcome by using cell cultures with smaller antenna sizes packed to high cell density cultures, thus allowing good light penetration into the inner sections of the reactor. We engineered a new small PSII antenna size Chlamydomonas reinhardtii strain with improved photon conversion efficiency and increased growth rates under high light conditions. We achieved this goal by transformation of a permanently active variant NAB1* of the LHC translation repressor NAB1 to reduce antenna size via translation repression. NAB1* expression was demonstrated in Stm6Glc4T7 (T7), leading to a reduction of LHC antenna size by 10-17%. T7 showed a approximately 50% increase of photosynthetic efficiency (PhiPSII) at saturating light intensity compared to the parental strain. T7 converted light to biomass with much higher efficiencies with a approximately 50% improved mid log growth phase. Moreover, T7 cultures reached higher densities when grown in large-scale bioreactors. Thus, the phenotype of strain T7 may have important implications for biotechnological applications in which photosynthetic microalgae are used for large-scale culturing as an alternative plant biomass source.
Publisher: Elsevier BV
Date: 12-2007
Publisher: Springer Science and Business Media LLC
Date: 12-2005
DOI: 10.1039/B506923H
Abstract: Solar energy capture, conversion into chemical energy and biopolymers by photoautotrophic organisms, is the basis for almost all life on Earth. A broad range of organisms have developed complex molecular machinery for the efficient conversion of sunlight to chemical energy over the past 3 billion years, which to the present day has not been matched by any man-made technologies. Chlorophyll photochemistry within photosystem II (PSII) drives the water-splitting reaction efficiently at room temperature, in contrast with the thermal dissociation reaction that requires a temperature of ca. 1550 K. The successful elucidation of the high-resolution structure of PSII, and in particular the structure of its Mn(4)Ca cluster provides an invaluable blueprint for designing solar powered biotechnologies for the future. This knowledge, combined with new molecular genetic tools, fully sequenced genomes, and an ever increasing knowledge base of physiological processes of oxygenic phototrophs has inspired scientists from many countries to develop new biotechnological strategies to produce renewable CO(2)-neutral energy from sunlight. This review focuses particularly on the potential of use of cyanobacteria and microalgae for biohydrogen production. Specifically this article reviews the predicted size of the global energy market and the constraints of global warming upon it, before detailing the complex set of biochemical pathways that underlie the photosynthetic process and how they could be modified for improved biohydrogen production.
Publisher: Oxford University Press (OUP)
Date: 04-2014
Abstract: Photosynthetic organisms developed multiple strategies for balancing light-harvesting versus intracellular energy utilization to survive ever-changing environmental conditions. The light-harvesting complex (LHC) protein family is of paramount importance for this function and can form light-harvesting pigment protein complexes. In this work, we describe detailed analyses of the photosystem II (PSII) LHC protein LHCBM9 of the microalga Chlamydomonas reinhardtii in terms of expression kinetics, localization, and function. In contrast to most LHC members described before, LHCBM9 expression was determined to be very low during standard cell cultivation but strongly increased as a response to specific stress conditions, e.g., when nutrient availability was limited. LHCBM9 was localized as part of PSII supercomplexes but was not found in association with photosystem I complexes. Knockdown cell lines with 50 to 70% reduced amounts of LHCBM9 showed reduced photosynthetic activity upon illumination and severe perturbation of hydrogen production activity. Functional analysis, performed on isolated PSII supercomplexes and recombinant LHCBM9 proteins, demonstrated that presence of LHCBM9 resulted in faster chlorophyll fluorescence decay and reduced production of singlet oxygen, indicating upgraded photoprotection. We conclude that LHCBM9 has a special role within the family of LHCII proteins and serves an important protective function during stress conditions by promoting efficient light energy dissipation and stabilizing PSII supercomplexes.
Publisher: Springer Science and Business Media LLC
Date: 12-02-2015
DOI: 10.1007/S00425-015-2249-9
Abstract: A 44-base-pair region in the Chlamydomonas reinhardtii LHCBM9 promoter is essential for sulphur responsiveness. The photosynthetic light-harvesting complex (LHC) proteins play essential roles both in light capture, the first step of photosynthesis, and in photoprotective mechanisms. In contrast to the other LHC proteins and the majority of photosynthesis proteins, the Chlamydomonas reinhardtii photosystem II-associated LHC protein, LHCBM9, was recently reported to be up-regulated under sulphur deprivation conditions, which also induce hydrogen production. Here, we examined the sulphur responsiveness of the LHCBM9 gene at the transcriptional level, through promoter deletion analysis. The LHCBM9 promoter was found to be responsive to sulphur deprivation, with a 44-base-pair region between nucleotide positions -136 and -180 relative to the translation start site identified as essential for this response. Anaerobiosis was found to enhance promoter activity under sulphur deprivation conditions, however, alone was unable to induce promoter activity. The study of LHCBM9 is of biological and biotechnological importance, as its expression is linked to photobiological hydrogen production, theoretically the most efficient process for biofuel production, while the simplicity of using an S-deprivation trigger enables the development of a novel C. reinhardtii-inducible promoter system based on LHCBM9.
Publisher: Elsevier BV
Date: 02-1999
Publisher: Springer International Publishing
Date: 2017
Publisher: Springer International Publishing
Date: 2022
DOI: 10.1007/10_2022_211
Publisher: Elsevier BV
Date: 10-2007
DOI: 10.1016/J.JSB.2007.07.005
Abstract: Edge-detection algorithms have the potential to play an increasingly important role both in single particle analysis (for the detection of randomly oriented particles), and in tomography (for the segmentation of 3D volumes). However, the majority of traditional linear filters are significantly affected by noise as well as artefacts, and offer limited selectivity. The Bilateral edge filter presented here is an adaptation of the Bilateral filter [Jiang, W., Baker, M.L., Wu, Q., Bajaj, C., Chiu, W., 2003. Applications of a bilateral denoising filter in biological electron microscopy. J. Struct. Biol. 144, 114-122] designed for enhanced edge detection. It uses photometric weighting to identify significant discontinuities (representing edges), minimizing artefacts and noise. Compared with common edge-detectors (LoG, Marr-Hildreth) the Bilateral edge filter yielded significantly better results. Indeed data was of a similar quality to that of the Canny edge-detector, which is considered as a leading standard in edge detection [Basu, M., 2002. Gaussian-based edge-detection methods-a survey. IEEE Trans. Syst. Man Cybern. C Appl. Rev. 32, 252-260]. Compared to the Canny edge-detector the Bilateral edge-detector has the advantages that it only requires the adjustment of a single parameter, is theoretically faster for reasonably sized images, and can be used in selective contrast enhancement of images. The simplicity and speed of the filter for single particle and tomographic analysis are discussed.
Publisher: Elsevier BV
Date: 03-2009
DOI: 10.1016/J.STR.2008.12.020
Abstract: Vps4 is a AAA ATPase that mediates endosomal membrane protein sorting. It is also a host factor hijacked by a erse set of clinically important viruses, including HIV and Ebola, to facilitate viral budding. Here we present the three-dimensional structure of the hydrolysis-defective Vps4p(E233Q) mutant. Single-particle analysis, multiangle laser light scattering, and the docking of independently determined atomic models of Vps4 monomers reveal a complex with C6 point symmetry, distinguishing between a range of previously suggested oligomeric states (8-14 subunits). The 3D reconstruction also reveals a tail-to-tail subunit organization between the two rings of the complex and identifies the location of domains critical to complex assembly and interaction with partner proteins. Our refined Vps4 structure is better supported by independent lines of evidence than those previously proposed, and provides insights into the mechanism of endosomal membrane protein sorting and viral envelope budding.
Publisher: American Chemical Society (ACS)
Date: 21-12-2010
DOI: 10.1021/LA103743E
Abstract: Fluorinated hipaths are a fascinating class of compounds, which, despite significant challenges associated with their syntheses, have found use across a number of areas of biotechnology. Applications range from the in vitro stabilization of membrane proteins to the development of enhanced stability intravenous drug and gene delivery systems. More recently, monolayer-forming fluorinated lipids have found use in the 2D crystallization of detergent-solubilized hydrophobic or partially hydrophobic proteins at the air-water interface. In this study, we investigate the surface properties of a novel suite of monolayer forming, partially fluorinated lipids. These modular lipid structures contain a densely fluorinated insertion in the hydrocarbon tail and a synthetically modifiable headgroup. Analyses of surface-pressure area isotherms and X-ray reflectometry profiles reveal that the lipids spread into fluid monolayers and are more compressible than their non-fluorinated counterparts. Furthermore, the data support a model whereby the partially fluorinated chains of the lipid tails form a film which is fundamentally incompatible with detergents and other destabilizing hipaths.
Publisher: Wiley
Date: 08-1997
Publisher: Elsevier BV
Date: 09-2001
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.JBIOTEC.2007.05.017
Abstract: Phototrophic organisms use photosynthesis to convert solar energy into chemical energy. In nature, the chemical energy is stored in a erse range of biopolymers. These sunlight-derived, energy-rich biopolymers can be converted into environmentally clean and CO(2) neutral fuels. A select group of photosynthetic microorganisms have developed the ability to extract and ert protons and electrons derived from water to chloroplast hydrogenase(s) to produce molecular H(2) fuel. Here, we describe the development and characterization of C. reinhardtii strains, derived from the high H(2) production mutant Stm6, into which the HUP1 (hexose uptake protein) hexose symporter from Chlorella kessleri was introduced. The isolated cell lines can use externally supplied glucose for heterotrophic growth in the dark. More importantly, external glucose supply (1mM) was shown to increase the H(2) production capacity in strain Stm6Glc4 to approximately 150% of that of the high-H(2) producing strain, Stm6. This establishes the foundations for a new fuel production process in which H(2)O and glucose can simultaneously be used for H(2) production. It also opens new perspectives on future strategies for improving bio-H(2) production efficiency under natural day/night regimes and for using sugar waste material for energy production in green algae as photosynthetic catalysts.
Publisher: Springer Science and Business Media LLC
Date: 02-2010
DOI: 10.1038/NBT0210-126
Publisher: Public Library of Science (PLoS)
Date: 29-03-2012
Publisher: American Chemical Society (ACS)
Date: 1996
DOI: 10.1021/BI961382H
Publisher: Bentham Science Publishers Ltd.
Date: 24-06-2016
Publisher: Springer International Publishing
Date: 2015
Publisher: Elsevier BV
Date: 05-2021
Publisher: Proceedings of the National Academy of Sciences
Date: 25-09-2018
Abstract: To optimize photosynthetic performance and minimize photooxidative damage, photosynthetic organisms evolved to efficiently balance light energy absorption and electron transport with cellular energy requirements under constantly changing light conditions. The regulation of linear electron flow (LEF) and cyclic electron flow (CEF) contributes to this fine-tuning. Here we present a model of the formation and structural molecular organization of a CEF-performing photosystem I (PSI)–light harvesting complex I (LHCI)–cytochrome (cyt) b 6 f supercomplex from the green alga Chlamydomonas reinhardtii . Such a structural arrangement could modulate the distinct operation of LEF and CEF to optimize light energy utilization, despite the same in idual structural units contributing to these two different functional modes.
Publisher: American Society for Microbiology
Date: 11-2008
DOI: 10.1128/EC.00418-07
Abstract: Photobiological hydrogen production using microalgae is being developed into a promising clean fuel stream for the future. In this study, microarray analyses were used to obtain global expression profiles of mRNA abundance in the green alga Chlamydomonas reinhardtii at different time points before the onset and during the course of sulfur-depleted hydrogen production. These studies were followed by real-time quantitative reverse transcription-PCR and protein analyses. The present work provides new insights into photosynthesis, sulfur acquisition strategies, and carbon metabolism-related gene expression during sulfur-induced hydrogen production. A general trend toward repression of transcripts encoding photosynthetic genes was observed. In contrast to all other LHCBM genes, the abundance of the LHCBM9 transcript (encoding a major light-harvesting polypeptide) and its protein was strongly elevated throughout the experiment. This suggests a major remodeling of the photosystem II light-harvesting complex as well as an important function of LHCBM9 under sulfur starvation and photobiological hydrogen production. This paper presents the first global transcriptional analysis of C. reinhardtii before, during, and after photobiological hydrogen production under sulfur deprivation.
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.CBPA.2013.03.030
Abstract: Herein we examine the potential role that microalgae might play in the approaching challenges of energy and fuel security, and food and water supply. Microalgal production systems remain the subject of controversy however, generally consisting of arguments about the economic and environment sustainability of these systems. We discuss these aspects and draw some parallels with other systems to highlight real advantages and obstacles to expanding the modern microalgal industry. Emerging alternative production models and the relatively early developmental state of the microalgal biofuels industry provide room for extensive innovation that has the potential to bring the technology to a highly productive maturity.
Publisher: Oxford University Press (OUP)
Date: 31-07-2006
DOI: 10.1017/S1431927606062465
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006
Publisher: Elsevier BV
Date: 08-2023
Publisher: Elsevier BV
Date: 10-2010
DOI: 10.1016/J.TPLANTS.2010.06.003
Abstract: Climate change mitigation, economic growth and stability, and the ongoing depletion of oil reserves are all major drivers for the development of economically rational, renewable energy technology platforms. Microalgae have re-emerged as a popular feedstock for the production of biofuels and other more valuable products. Even though integrated microalgal production systems have some clear advantages and present a promising alternative to highly controversial first generation biofuel systems, the associated hype has often exceeded the boundaries of reality. With a growing number of recent analyses demonstrating that despite the hype, these systems are conceptually sound and potentially sustainable given the available inputs, we review the research areas that are key to attaining economic reality and the future development of the industry.
Publisher: American Chemical Society (ACS)
Date: 27-03-2002
DOI: 10.1021/BI0120650
Abstract: The determination of the structure of PSII at high resolution is required in order to fully understand its reaction mechanisms. Two-dimensional crystals of purified highly active Synechococcus elongatus PSII dimers were obtained by in vitro reconstitution. Images of these crystals were recorded by electron cryo-microscopy, and their analysis revealed they belong to the two-sided plane group p22(1)2(1), with unit cell parameters a = 121 A, b = 333 A, and alpha = 90 degrees. From these crystals, a projection map was calculated to a resolution of approximately 16 A. The reliability of this projection map is confirmed by its close agreement with the recently presented three-dimensional model of the same complex obtained by X-ray crystallography. Comparison of the projection map of the Synechococcus elongatus PSII complex with data obtained by electron crystallography of the spinach PSII core dimer reveals a similar organization of the main transmembrane subunits. However, some differences in density distribution between the cyanobacterial and higher plant PSII complexes exist, especially in the outer region of the complex between CP43 and cytochrome b(559) and adjacent to the B-helix of the D1 protein. These differences are discussed in terms of the number and organization of some of the PSII low molecular weight subunits.
Publisher: Springer Science and Business Media LLC
Date: 06-1999
DOI: 10.1038/9341
Abstract: Here we present cryoelectron crystallographic analysis of an isolated dimeric oxygen-evolving complex of photosystem II (at a resolution of approximately 0.9 nm), revealing that the D1-D2 reaction center (RC) proteins are centrally located between the chlorophyll-binding proteins, CP43 and CP47. This conclusion supports the hypothesis that photosystems I and II have similar structural features and share a common evolutionary origin. Additional density connecting the two halves of the dimer, which was not observed in a recently described CP47-RC complex that did not include CP43, may be attributed to the small subunits that are involved in regulating secondary electron transfer, such as PsbH. These subunits are possibly also required for stabilization of the dimeric photosystem II complex. This complex, containing at least 29 transmembrane helices in its asymmetric unit, represents one of the largest membrane protein complexes studied at this resolution.
Publisher: International Union of Crystallography (IUCr)
Date: 19-04-2006
Publisher: Elsevier BV
Date: 09-2016
Location: United Kingdom of Great Britain and Northern Ireland
Location: Australia
Start Date: 11-2008
End Date: 12-2010
Amount: $286,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 06-2004
Amount: $60,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2015
End Date: 08-2018
Amount: $340,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 12-2015
Amount: $940,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2020
End Date: 06-2021
Amount: $623,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2004
End Date: 12-2006
Amount: $360,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 12-2013
Amount: $375,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2005
End Date: 12-2010
Amount: $25,064.00
Funder: Australian Research Council
View Funded ActivityStart Date: 10-2019
End Date: 12-2022
Amount: $589,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2004
End Date: 12-2004
Amount: $10,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2015
End Date: 12-2015
Amount: $590,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2010
End Date: 12-2012
Amount: $309,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2005
End Date: 06-2008
Amount: $380,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2018
End Date: 12-2019
Amount: $3,189,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2015
End Date: 12-2017
Amount: $443,900.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 09-2007
Amount: $140,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2016
End Date: 12-2019
Amount: $584,800.00
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2022
End Date: 03-2025
Amount: $470,271.00
Funder: Australian Research Council
View Funded ActivityStart Date: 11-2008
End Date: 12-2012
Amount: $674,345.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2019
End Date: 12-2022
Amount: $460,800.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2004
End Date: 12-2004
Amount: $10,000.00
Funder: Australian Research Council
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