ORCID Profile
0000-0002-6551-4657
Current Organisation
Diamond Light Source (United Kingdom)
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Biochemistry and Cell Biology | Receptors and Membrane Biology | Structural Biology (incl. Macromolecular Modelling) | Bioinorganic Chemistry
Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in the Biological Sciences |
Publisher: International Union of Crystallography (IUCr)
Date: 25-03-2003
DOI: 10.1107/S090744490300194X
Abstract: The structure of dimeric cytochrome c(3) from the sulfate-reducing bacterium Desulfovibrio gigas, diDg, obtained by ab initio methods was further refined to 1.2 A resolution, giving final reliability factors of R(free) = 14.8% and R = 12.4%. This cytochrome is a dimer of tetraheme cytochrome c(3) molecules covalently linked by two solvent-accessible disulfide bridges, a characteristic unique to members of the cytochrome c(3) superfamily. Anisotropic analysis using the semi-rigid TLS method shows different behaviour for analogous loops in each monomer arising from their different packing environments. A detailed sequence and structural comparison with all other known cytochrome c(3) domains in single- and multi-domain cytochromes c(3) shows the presence of structurally conserved regions in this family, despite the high variability of the amino-acid sequence. An internal water molecule is conserved in a common structural arrangement in all c(3) tetraheme domains, indicating a probable electron-transfer pathway between hemes I and II. Unique features of diDg are an internal methionine residue close to heme I and to one of the axial ligands of heme III, where all other structures of the cytochrome c(3) superfamily have a phenylalanine, and a rather unusual CXXXCH heme-binding motif only found so far in this cytochrome.
Publisher: American Chemical Society (ACS)
Date: 19-10-2011
DOI: 10.1021/CG101379P
Publisher: Springer Science and Business Media LLC
Date: 09-01-2017
DOI: 10.1038/SREP40165
Abstract: Type II NADH:quinone oxidoreductase (NDH-2) is central to the respiratory chains of many organisms. It is not present in mammals so may be exploited as an antimicrobial drug target or used as a substitute for dysfunctional respiratory complex I in neuromuscular disorders. NDH-2 is a single-subunit monotopic membrane protein with just a flavin cofactor, yet no consensus exists on its mechanism. Here, we use steady-state and pre-steady-state kinetics combined with mutagenesis and structural studies to determine the mechanism of NDH-2 from Caldalkalibacillus thermarum . We show that the two substrate reactions occur independently, at different sites, and regardless of the occupancy of the partner site. We conclude that the reaction pathway is determined stochastically, by the substrate roduct concentrations and dissociation constants, and can follow either a ping-pong or ternary mechanism. This mechanistic versatility provides a unified explanation for all extant data and a new foundation for the development of therapeutic strategies.
Publisher: International Union of Crystallography (IUCr)
Date: 2015
DOI: 10.1107/S1600577514021717
Abstract: MX1 is a bending-magnet crystallography beamline at the 3 GeV Australian Synchrotron. The beamline delivers hard X-rays in the energy range from 8 to 18 keV to a focal spot at the s le position of 120 µm FWHM. The beamline endstation and ancillary equipment facilitate local and remote access for both chemical and biological macromolecular crystallography. Here, the design of the beamline and endstation are discussed. The beamline has enjoyed a full user program for the last seven years and scientific highlights from the user program are also presented.
Publisher: MyJove Corporation
Date: 02-09-2012
DOI: 10.3791/4001
Publisher: The Royal Society
Date: 06-2019
DOI: 10.1098/RSOB.190066
Abstract: The crystal structure of the F 1 -catalytic domain of the adenosine triphosphate (ATP) synthase has been determined from the pathogenic anaerobic bacterium Fusobacterium nucleatum . The enzyme can hydrolyse ATP but is partially inhibited. The structure is similar to those of the F 1 -ATPases from Caldalkalibacillus thermarum , which is more strongly inhibited in ATP hydrolysis, and in Mycobacterium smegmatis , which has a very low ATP hydrolytic activity. The β E -subunits in all three enzymes are in the conventional ‘open’ state, and in the case of C. thermarum and M. smegmatis , they are occupied by an ADP and phosphate (or sulfate), but in F. nucleatum , the occupancy by ADP appears to be partial. It is likely that the hydrolytic activity of the F. nucleatum enzyme is regulated by the concentration of ADP, as in mitochondria.
Publisher: International Union of Crystallography (IUCr)
Date: 27-11-2003
DOI: 10.1107/S0907444903025861
Abstract: The hybrid cluster protein (HCP) from the sulfate-reducing bacteria Desulfovibrio desulfuricans ATCC 27774 has been isolated and crystallized anaerobically. The protein s le used in the crystallization studies was several months old, having been stored at 193 K, and initial crystal structure studies were unable to fully resolve details of the hybrid cluster despite the use of high-resolution data to 1.25 A collected at the ESRF, Grenoble, France. Full elucidation of the structure has only become possible with the complete knowledge of the as-isolated and fully reduced crystal structures. The analysis clarifies the significant movements in the position of the Fe atom linked to the persulfide moiety in the oxidized as-isolated protein and the S atom of the persulfide itself as the protein is reduced. The structures of the as-isolated and reduced states are discussed in terms of the putative function of the HCP proteins.
Publisher: International Union of Crystallography (IUCr)
Date: 2019
DOI: 10.1107/S2053230X18016527
Abstract: The glutathione reductase (GR) from Streptococcus pneumoniae is a flavoenzyme that catalyzes the reduction of oxidized glutathione (GSSG) to its reduced form (GSH) in the cytoplasm of this bacterium. The maintenance of an intracellular pool of GSH is critical for the detoxification of reactive oxygen and nitrogen species and for intracellular metal tolerance to ions such as zinc. Here, S. pneumoniae GR ( Sp GR) was overexpressed and purified and its crystal structure determined at 2.56 Å resolution. Sp GR shows overall structural similarity to other characterized GRs, with a dimeric structure that includes an antiparallel β-sheet at the dimer interface. This observation, in conjunction with comparisons with the interface structures of other GR enzymes, allows the classification of these enzymes into three classes. Analyses of the kinetic properties of Sp GR revealed a significantly higher value for K m(GSSG) (231.2 ± 24.7 µ M ) in comparison to other characterized GR enzymes .
Publisher: International Union of Crystallography (IUCr)
Date: 14-05-2008
Publisher: Springer Science and Business Media LLC
Date: 04-10-2016
DOI: 10.1038/NCOMMS13014
Abstract: The assembly and regulation of viral capsid proteins into highly ordered macromolecular complexes is essential for viral replication. Here, we utilize crystal structures of the capsid protein from the smallest and simplest known viruses capable of autonomously replicating in animal cells, circoviruses, to establish structural and mechanistic insights into capsid morphogenesis and regulation. The beak and feather disease virus, like many circoviruses, encode only two genes: a capsid protein and a replication initiation protein. The capsid protein forms distinct macromolecular assemblies during replication and here we elucidate these structures at high resolution, showing that these complexes reverse the exposure of the N-terminal arginine rich domain responsible for DNA binding and nuclear localization. We show that assembly of these complexes is regulated by single-stranded DNA (ssDNA), and provide a structural basis of capsid assembly around single-stranded DNA, highlighting novel binding interfaces distinct from the highly positively charged N-terminal ARM domain.
Publisher: Elsevier BV
Date: 08-2010
Publisher: Springer Science and Business Media LLC
Date: 17-12-2015
DOI: 10.1038/NCOMMS10140
Abstract: Diacylglycerol kinase catalyses the ATP-dependent conversion of diacylglycerol to phosphatidic acid in the plasma membrane of Escherichia coli . The small size of this integral membrane trimer, which has 121 residues per subunit, means that available protein must be used economically to craft three catalytic and substrate-binding sites centred about the membrane/cytosol interface. How nature has accomplished this extraordinary feat is revealed here in a crystal structure of the kinase captured as a ternary complex with bound lipid substrate and an ATP analogue. Residues, identified as essential for activity by mutagenesis, decorate the active site and are rationalized by the ternary structure. The γ-phosphate of the ATP analogue is positioned for direct transfer to the primary hydroxyl of the lipid whose acyl chain is in the membrane. A catalytic mechanism for this unique enzyme is proposed. The active site architecture shows clear evidence of having arisen by convergent evolution.
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.BBRC.2019.08.056
Abstract: Acinetobacter baumannii (A. baumannii) is a clinically relevant, highly drug-resistant pathogen of global concern. An attractive approach to drug design is to specifically target the type II fatty acid synthesis (FASII) pathway which is critical in Gram negative bacteria and is significantly different to the type I fatty acid synthesis (FASI) pathway found in mammals. Enzymes involved in FASII include members of the short-chain dehydrogenase/reductase (SDR) superfamily. SDRs are capable of performing a erse range of biochemical reactions against a broad spectrum of substrates whilst maintaining conserved structural features and sequence motifs. Here, we use X-ray crystallography to describe the structure of an SDR from the multi-drug resistant bacteria A. baumannii, previously annotated as a putative FASII FabG enzyme. The protein was recombinantly expressed, purified, and crystallized. The protein crystals diffracted to 2.0 Å and the structure revealed a FabG-like fold. Functional assays revealed, however, that the protein was not active against the FabG substrate, acetoacetyl-CoA. This study highlights that database annotations may show the necessary structural hallmarks of such proteins, however, they may not be able to cleave substrates that are typical of FabG enzymes. These results are important for the selection of target enzymes in future drug development.
Publisher: Elsevier BV
Date: 12-2017
Publisher: Wiley
Date: 05-02-2008
DOI: 10.1016/J.FEBSLET.2008.01.041
Abstract: Detailed structural models of di-cluster seven-iron ferredoxins constitute a valuable resource for folding and stability studies relating the metal cofactors' role in protein stability. The here reported, hemihedric twinned crystal structure at 2.0 A resolution from Acidianus ambivalens ferredoxin, shows an integral 103 residues, physiologically relevant native form composed by a N-terminal extension comprising a His/Asp Zn(2+) site and the ferredoxin (betaalphabeta)(2) core, which harbours intact clusters I and II, a [3Fe-4S](1+/0) and a [4Fe-4S](2+/1+) centres. This is in contrast with the previously available ferredoxin structure from Sulfolofus tokodai, which was obtained from an artificial oxidative conversion with two [3Fe-4S](1+/0) centres and poor definition around cluster II.
Publisher: Cold Spring Harbor Laboratory
Date: 18-11-2021
DOI: 10.1101/2021.11.17.468889
Abstract: The multiple functions of PGRMC1, the archetypal heme-binding eukaryotic MAPR family member, include steroidogenic regulation, membrane trafficking, and steroid responsiveness. The interrelationships between these functions are currently poorly understood. Previous work has shown that different MAPR subclasses were present early in eukaryotic evolution, and that tyrosine phosphorylated residues appeared in the eumetazoan ancestor, coincident with a gastrulation organizer. Here we show that MAPR proteins are related to a newly recognized class of prokaryotic cytochrome-b 5 domain proteins. Our first solved structure of this new class exhibits shared MAPR-like folded architecture and heme-binding orientation. We also report that a protein subgroup from Candidate Phyla Radiation bacteria shares MAPR-like heme-interacting tyrosines. Our results support bacterial origins for both PGRMC1 and CYP51A, that catalyze the meiosis-associated 14-demethylation of the first sterol lanosterol from yeast to humans. We propose that eukaryotic acquisition of a membrane-trafficking function related to sterol metabolism was associated with the appearance of MAPR genes early in eukaryotic evolution.
Publisher: American Chemical Society (ACS)
Date: 02-03-2017
DOI: 10.1021/ACS.BIOCHEM.6B01049
Abstract: Mycobacteria contain a large number of highly ergent species and exhibit unusual lipid metabolism profiles, believed to play important roles in immune invasion. Thioesterases modulate lipid metabolism through the hydrolysis of activated fatty-acyl CoAs multiple copies are present in mycobacteria, yet many remain uncharacterized. Here, we undertake a comprehensive structural and functional analysis of a TesB thioesterase from Mycobacterium avium (MaTesB). Structural superposition with other TesB thioesterases reveals that the Asp active site residue, highly conserved across a wide range of TesB thioesterases, is mutated to Ala. Consistent with these structural data, the wild-type enzyme failed to hydrolyze an extensive range of acyl-CoA substrates. Mutation of this residue to an active Asp residue restored activity against a range of medium-chain length fatty-acyl CoA substrates. Interestingly, this Ala mutation is highly conserved across a wide range of Mycobacterium species but not found in any other bacteria or organism. Our structural homology analysis revealed that at least one other TesB acyl-CoA thioesterase also contains an Ala residue at the active site, while two other Mycobacterium TesB thioesterases harbor an Asp residue at the active site. The inactive TesBs display a common quaternary structure that is distinct from that of the active TesB thioesterases. Investigation of the effect of expression of either the catalytically active or inactive MaTesB in Mycobacterium smegmatis exposed, to the best of our knowledge, the first genotype-phenotype association implicating a mycobacterial tesB gene. This is the first report that mycobacteria encode active and inactive forms of thioesterases, the latter of which appear to be unique to mycobacteria.
Publisher: Springer Science and Business Media LLC
Date: 2011
DOI: 10.1038/NATURE09665
Publisher: International Union of Crystallography (IUCr)
Date: 26-06-2001
DOI: 10.1107/S2056989020008099
Abstract: Exceptionally large crystals of posnjakite, Cu 4 SO 4 (OH) 6 (H 2 O), formed during corrosion of a Swagelock(tm) Snubber copper gasket within the MX1 beamline at the ANSTO-Melbourne, Australian Synchrotron. The crystal structure was solved using synchrotron radiation to R 1 = 0.029 and revealed a structure based upon [Cu 4 (OH) 6 (H 2 O)O] sheets, which contain Jahn–Teller-distorted Cu octahedra. The sulfate tetrahedra are bonded to one side of the sheet via corner sharing and linked to successive sheets via extensive hydrogen bonds. The sulfate tetrahedra are split and rotated, which enables additional hydrogen bonds.
Publisher: Elsevier BV
Date: 07-2018
Publisher: International Union of Crystallography (IUCr)
Date: 23-09-2017
DOI: 10.1107/S2053230X17013073
Abstract: Type II NADH:quinone oxidoreductase (NDH-2) is a respiratory enzyme found in the electron-transport chain of many species, with the exception of mammals. It is a 40–70 kDa single-subunit monotopic membrane protein that catalyses the oxidation of NADH and the reduction of quinone molecules via the cofactor FAD. NDH-2 is a promising new target for drug development given its essential role in many bacterial species and intracellular parasites. Only two bacterial NDH-2 structures have been reported and these structures are at moderate resolution (2.3–2.5 Å). In this communication, a new crystallization platform is reported that produced high-quality NDH-2 crystals that diffracted to high resolution (2.15 Å). The high-resolution NDH-2 structure was used for in silico quinone substrate-docking studies to investigate the binding poses of menadione and ubiquinone molecules. These studies revealed that a very limited number of molecular interactions occur at the quinone-binding site of NDH-2. Given that the conformation of the active site is well defined, this high-resolution structure is potentially suitable for in silico inhibitor-compound screening and ligand-docking applications.
Publisher: International Union of Crystallography (IUCr)
Date: 30-09-2014
DOI: 10.1107/S1399004714016174
Abstract: The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The service automatically receives and archives raw diffraction data, related metadata and preliminary results of automated data-processing workflows. Data are able to be shared with collaborators and opened to the public. In the nine months since its deployment in August 2013, the service has handled over 22.4 TB of raw data (∼1.7 million diffraction images). Several real ex les from the Australian crystallographic community are described that illustrate the advantages of the approach, which include real-time online data access and fully redundant, secure storage. Discoveries in biological sciences increasingly require multidisciplinary approaches. With this in mind, Store.Synchrotron has been developed as a component within a greater service that can combine data from other instruments at the Australian Synchrotron, as well as instruments at the Australian neutron source ANSTO. It is therefore envisaged that this will serve as a model implementation of raw data archiving and dissemination within the structural biology research community.
Publisher: American Chemical Society (ACS)
Date: 16-02-2011
DOI: 10.1021/CG101384P
Publisher: Springer Science and Business Media LLC
Date: 04-01-2021
DOI: 10.1038/S41467-020-20194-0
Abstract: SOX (SRY-related HMG-box) transcription factors perform critical functions in development and cell differentiation. These roles depend on precise nuclear trafficking, with mutations in the nuclear targeting regions causing developmental diseases and a range of cancers. SOX protein nuclear localization is proposed to be mediated by two nuclear localization signals (NLSs) positioned within the extremities of the DNA-binding HMG-box domain and, although mutations within either cause disease, the mechanistic basis has remained unclear. Unexpectedly, we find here that these two distantly positioned NLSs of SOX2 contribute to a contiguous interface spanning 9 of the 10 ARM domains on the nuclear import adapter IMPα3. We identify key binding determinants and show this interface is critical for neural stem cell maintenance and for Drosophila development. Moreover, we identify a structural basis for the preference of SOX2 binding to IMPα3. In addition to defining the structural basis for SOX protein localization, these results provide a platform for understanding how mutations and post-translational modifications within these regions may modulate nuclear localization and result in clinical disease, and also how other proteins containing multiple NLSs may bind IMPα through an extended recognition interface.
Publisher: International Union of Crystallography (IUCr)
Date: 26-08-2006
Publisher: Elsevier BV
Date: 04-2011
Publisher: Springer Science and Business Media LLC
Date: 12-09-2018
DOI: 10.1038/S41467-018-05928-5
Abstract: Seven human isoforms of importin α mediate nuclear import of cargo in a tissue- and isoform-specific manner. How nuclear import adaptors differentially interact with cargo harbouring the same nuclear localisation signal (NLS) remains poorly understood, as the NLS recognition region is highly conserved. Here, we provide a structural basis for the nuclear import specificity of W proteins in Hendra and Nipah viruses. We determine the structural interfaces of these cargo bound to importin α1 and α3, identifying a 2.4-fold more extensive interface and 50-fold higher binding affinity for importin α3. Through the design of importin α1 and α3 chimeric and mutant proteins, together with structures of cargo-free importin α1 and α3 isoforms, we establish that the molecular basis of specificity resides in the differential positioning of the armadillo repeats 7 and 8. Overall, our study provides mechanistic insights into a range of important nucleocytoplasmic transport processes reliant on isoform adaptor specificity.
Publisher: International Union of Crystallography (IUCr)
Date: 03-04-2018
DOI: 10.1107/S1600577518003120
Abstract: MX2 is an in-vacuum undulator-based crystallography beamline at the 3 GeV Australian Synchrotron. The beamline delivers hard X-rays in the energy range 4.8–21 keV to a focal spot of 22 × 12 µm FWHM (H × V). At 13 keV the flux at the s le is 3.4 × 10 12 photons s −1 . The beamline endstation allows robotic handling of cryogenic s les via an updated SSRL SAM robot. This beamline is ideal for weakly diffracting hard-to-crystallize proteins, virus particles, protein assemblies and nucleic acids as well as smaller molecules such as inorganic catalysts and organic drug molecules. The beamline is now mature and has enjoyed a full user program for the last nine years. This paper describes the beamline status, plans for its future and some recent scientific highlights.
Publisher: Wiley
Date: 22-08-2022
Abstract: We recently reported that the membrane-associated progesterone receptor (MAPR) protein family (mammalian members: PGRMC1, PGRMC2, NEUFC and NENF) originated from a new class of prokaryotic cytochrome b
Publisher: Elsevier BV
Date: 03-2016
DOI: 10.1016/J.STR.2015.12.016
Abstract: Chaperonins are essential biological complexes assisting protein folding in all kingdoms of life. Whereas homooligomeric bacterial GroEL binds hydrophobic substrates non-specifically, the heterooligomeric eukaryotic CCT binds specifically to distinct classes of substrates. Sulfolobales, which survive in a wide range of temperatures, have evolved three different chaperonin subunits (α, β, γ) that form three distinct complexes tailored for different substrate classes at cold, normal, and elevated temperatures. The larger octadecameric β complexes cater for substrates under heat stress, whereas smaller hexadecameric αβ complexes prevail under normal conditions. The cold-shock complex contains all three subunits, consistent with greater substrate specificity. Structural analysis using crystallography and electron microscopy reveals the geometry of these complexes and shows a novel arrangement of the α and β subunits in the hexadecamer enabling incorporation of the γ subunit.
Publisher: American Society for Microbiology
Date: 15-06-2007
DOI: 10.1128/JB.00277-07
Abstract: Gellan gum is a widely used commercial material, available in many different forms. Its economic importance has led to studies into the biosynthesis of exopolysaccharide gellan gum, which is industrially prepared in high yields using Sphingomonas elodea ATCC 31461. Glucose-1-phosphate uridylyltransferase mediates the reversible conversion of glucose-1-phosphate and UTP into UDP-glucose and pyrophosphate, which is a key step in the biosynthetic pathway of gellan gums. Here we present the X-ray crystal structure of the glucose-1-phosphate uridylyltransferase from S. elodea . The S. elodea enzyme shares strong monomeric similarity with glucose-1-phosphate thymidylyltransferase, several structures of which are known, although the quaternary structures of the active enzymes are rather different. A detailed comparison between S. elodea glucose-1-phosphate uridylyltransferase and available thymidylyltransferases is described and shows remarkable structural similarities, despite the low sequence identities between the two ergent groups of proteins.
Publisher: Life Science Alliance, LLC
Date: 12-09-2019
Abstract: Assembly factors play key roles in the biogenesis of many multi-subunit protein complexes regulating their stability, activity, and the incorporation of essential cofactors. The human assembly factor Coa6 participates in the biogenesis of the Cu A site in complex IV (cytochrome c oxidase, COX). Patients with mutations in Coa6 suffer from mitochondrial disease due to complex IV deficiency. Here, we present the crystal structures of human Coa6 and the pathogenic W59C Coa6-mutant protein. These structures show that Coa6 has a 3-helical bundle structure, with the first 2 helices tethered by disulfide bonds, one of which likely provides the copper-binding site. Disulfide-mediated oligomerization of the W59C Coa6 protein provides a structural explanation for the loss-of-function mutation.
Publisher: Springer Science and Business Media LLC
Date: 25-03-2022
DOI: 10.1038/S41467-022-28851-2
Abstract: The MERS coronavirus (MERS-CoV) is a highly pathogenic, emerging virus that produces accessory proteins to antagonize the host innate immune response. The MERS-CoV ORF4b protein has been shown to bind preferentially to the nuclear import adapter IMPα3 in infected cells, thereby inhibiting NF-κB-dependent innate immune responses. Here, we report high-resolution structures of ORF4b bound to two distinct IMPα family members. Each exhibit highly similar binding mechanisms that, in both cases, lack a prototypical Lys bound at their P2 site. Mutations within the NLS region dramatically alter the mechanism of binding, which reverts to the canonical P2 Lys binding mechanism. Mutational studies confirm that the novel binding mechanism is important for its nuclear import, IMPα interaction, and inhibition of innate immune signaling pathways. In parallel, we determined structures of the nuclear binding domain of NF-κB component p50 bound to both IMPα2 and α3, demonstrating that p50 overlaps with the ORF4b binding sites, suggesting a basis for inhibition. Our results provide a detailed structural basis that explains how a virus can target the IMPα nuclear import adapter to impair immunity, and illustrate how small mutations in ORF4b, like those found in closely related coronaviruses such as HKU5, change the IMPα binding mechanism.
Publisher: Elsevier BV
Date: 2015
Publisher: Springer Science and Business Media LLC
Date: 15-05-2013
DOI: 10.1038/NATURE12179
Publisher: Springer Science and Business Media LLC
Date: 07-2012
DOI: 10.1038/NATURE11182
Publisher: Springer Science and Business Media LLC
Date: 29-03-2021
DOI: 10.1038/S41598-021-86400-1
Abstract: Treatments for ‘superbug’ infections are the focus for innovative research, as drug resistance threatens human health and medical practices globally. In particular, Acinetobacter baumannii ( Ab ) infections are repeatedly reported as difficult to treat due to increasing antibiotic resistance. Therefore, there is increasing need to identify novel targets in the development of different antimicrobials. Of particular interest is fatty acid synthesis, vital for the formation of phospholipids, lipopolysaccharides/lipooligosaccharides, and lipoproteins of Gram-negative envelopes. The bacterial type II fatty acid synthesis (FASII) pathway is an attractive target for the development of inhibitors and is particularly favourable due to the differences from mammalian type I fatty acid synthesis. Discrete enzymes in this pathway include two reductase enzymes: 3-oxoacyl-acyl carrier protein (ACP) reductase (FabG) and enoyl-ACP reductase (FabI). Here, we investigate annotated FabG homologs, finding a low-molecular weight 3-oxoacyl-ACP reductase, as the most likely FASII FabG candidate, and high-molecular weight 3-oxoacyl-ACP reductase (HMwFabG), showing differences in structure and coenzyme preference. To date, this is the second bacterial high-molecular weight FabG structurally characterized, following FabG4 from Mycobacterium. We show that Δ AbHMwfabG is impaired for growth in nutrient rich media and pellicle formation. We also modelled a third 3-oxoacyl-ACP reductase, which we annotated as Ab SDR. Despite containing residues for catalysis and the ACP coordinating motif, biochemical analyses showed limited activity against an acetoacetyl-CoA substrate in vitro. Inhibitors designed to target FabG proteins and thus prevent fatty acid synthesis may provide a platform for use against multidrug-resistant pathogens including A. baumannii .
Publisher: Cold Spring Harbor Laboratory
Date: 30-11-2021
DOI: 10.1101/2021.11.30.470528
Abstract: We recently reported that the membrane associated progesterone receptor (MAPR) protein family (mammalian members: PGRMC1, PGRMC2, NEUFC and NENF) originated from a new class of prokaryotic cytochrome b 5 (cytb 5 ) domain proteins, called cytb 5 M ( M APR-like). Relative to classical cytb 5 proteins, MAPR and ctyb 5M proteins shared unique sequence elements and a distinct heme binding orientation at an approximately 90⁰ rotation relative to classical cytb 5 , as demonstrated in the archetypal crystal structure of a cytb 5M protein (PDB accession number 6NZX). Here, we present the second crystal structure of an archaeal cytb 5M domain ( Methanococcoides burtonii WP_011499504.1, PDB:6VZ6). It exhibits similar heme-binding to the 6NZX cytb 5M , supporting the deduction that MAPR-like heme orientation was inherited from the prokaryotic ancestor of the original eukaryotic MAPR gene.
Location: United Kingdom of Great Britain and Northern Ireland
Location: Australia
Location: Portugal
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2021
End Date: 2025
Funder: National Health and Medical Research Council
View Funded ActivityStart Date: 2014
End Date: 2016
Funder: Australian Research Council
View Funded ActivityStart Date: 2014
End Date: 02-2017
Amount: $333,000.00
Funder: Australian Research Council
View Funded Activity