Can efficient algal variants of the photosynthetic CO2-fixing enzyme, Rubisco, be folded and assembled in functional forms in higher-plant plastids? We have shown that it is possible to alter the photosynthetic phenotype of a plant predictably and profoundly by engineering the plastid genome to replace the plant's CO2-fixing enzyme, Rubisco, with a bacterial homolog. Thus it may be possible to replace the plant enzyme with more efficient algal Rubiscos that would allow plants to grow with less l ....Can efficient algal variants of the photosynthetic CO2-fixing enzyme, Rubisco, be folded and assembled in functional forms in higher-plant plastids? We have shown that it is possible to alter the photosynthetic phenotype of a plant predictably and profoundly by engineering the plastid genome to replace the plant's CO2-fixing enzyme, Rubisco, with a bacterial homolog. Thus it may be possible to replace the plant enzyme with more efficient algal Rubiscos that would allow plants to grow with less light, less water or less fertiliser. Before such desirable changes to the plant phenotype can be realised, some complex issues of modification, folding and assembly of Rubisco subunits need to be resolved. This proposal addresses them.Read moreRead less
Enhancing plant photosynthesis by engineering the carbon dioxide (CO2)-fixing enzyme Rubisco. Improving the ability of crops to use water, sunlight and fertiliser more efficiently would have economic benefits for Australia and ease the environmental impacts associated with agricultural practices. Photosynthesis research has confirmed that such improvements are theoretically possible by enhancing the efficiency of the protein, Rubisco, which initiates the conversion of carbon dioxide into carbon ....Enhancing plant photosynthesis by engineering the carbon dioxide (CO2)-fixing enzyme Rubisco. Improving the ability of crops to use water, sunlight and fertiliser more efficiently would have economic benefits for Australia and ease the environmental impacts associated with agricultural practices. Photosynthesis research has confirmed that such improvements are theoretically possible by enhancing the efficiency of the protein, Rubisco, which initiates the conversion of carbon dioxide into carbon compounds required for growth. The biotechnological research proposed here uses unique capabilities to improve our understanding of structural features in Rubisco that influence its assembly and functional efficiency in plants. This knowledge will pave the way for transplanting more efficient Rubisco into crops to improve their growth.Read moreRead less
BIOCATALYSTS MINED FROM CYTOCHROME P450 LIBRARIES: AN INNOVATIVE TOOL FOR ACCELERATING DRUG DEVELOPMENT. The cytochrome P450s (P450s) are a family of enzymes that are perhaps the most versatile biological catalysts known. DNA shuffling is an emerging technique that takes the genes encoding families of enzymes and creates libraries of catalysts with both improved and novel properties. We will obtain proof of concept that shuffled P450 libraries can be screened and optimized for use as biocatalys ....BIOCATALYSTS MINED FROM CYTOCHROME P450 LIBRARIES: AN INNOVATIVE TOOL FOR ACCELERATING DRUG DEVELOPMENT. The cytochrome P450s (P450s) are a family of enzymes that are perhaps the most versatile biological catalysts known. DNA shuffling is an emerging technique that takes the genes encoding families of enzymes and creates libraries of catalysts with both improved and novel properties. We will obtain proof of concept that shuffled P450 libraries can be screened and optimized for use as biocatalysts in drug development. The methodologies developed here will overcome two critical bottlenecks in current drug development: the optimisation and metabolic profiling of new drug candidates. This will yield important benefits in accelerating the optimisation and safety testing of drugs under development.Read moreRead less
Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or ....Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or light. The most efficient Rubiscos are more complex, with two different types of subunits which, in plants, are encoded in different subcellular compartments (nucleus and plastid). This proposal addresses the challenges associated with complementary engineering both genomes to substitute foreign Rubiscos into higher-plant chloroplasts.Read moreRead less
Identifying potential barriers to transplanting modified forms of the CO2-fixing enzyme, Rubisco, into plants. Improving the ability of crops to use water, light and fertiliser more efficiently would have economic benefits and ease the environmental impacts associated with agricultural practices. It is thought that such improvements can be made by enhancing the efficiency of the photosynthetic protein, Rubisco, which fixes most of the CO2 in the biosphere. The research proposed here uses unique ....Identifying potential barriers to transplanting modified forms of the CO2-fixing enzyme, Rubisco, into plants. Improving the ability of crops to use water, light and fertiliser more efficiently would have economic benefits and ease the environmental impacts associated with agricultural practices. It is thought that such improvements can be made by enhancing the efficiency of the photosynthetic protein, Rubisco, which fixes most of the CO2 in the biosphere. The research proposed here uses unique Rubisco transplantation capabilities that I have developed to improve our fundamental understanding of how Rubisco is processed and its activity regulated in plants. This will pave the way for our ongoing efforts to engineer and transplant more efficient Rubisco into crops.Read moreRead less
The toxins of water-borne cyanobacteria: regulation and exploitation of their biosynthesis. Water quality is a major concern in Australia, as is the global need for new natural products with antibiotic activity. The mechanisms by which cyanobacteria produce toxins that reduce the quality of water may very well be the answer to the lack of novel medicinal compounds currently being discovered in nature. Encompassed in this one program are the aims of ameliorating the effects of toxic algal blooms ....The toxins of water-borne cyanobacteria: regulation and exploitation of their biosynthesis. Water quality is a major concern in Australia, as is the global need for new natural products with antibiotic activity. The mechanisms by which cyanobacteria produce toxins that reduce the quality of water may very well be the answer to the lack of novel medicinal compounds currently being discovered in nature. Encompassed in this one program are the aims of ameliorating the effects of toxic algal blooms as well as introducing the means for the design and synthesis of a range of novel bioactive products. The benefits include better water quality and biosafety management options, a new generation of drug design and discovery, and the associated transformation of environmental and medical research and education in Australia.Read moreRead less
Synthesis and assembly of bacterial repeat unit polysaccharides. Bacteria make an enormous range of surface polysaccharides. The complexity was first appreciated as antigenic diversity, but we now have hundreds of chemical structures and perhaps a hundred sequences of their gene clusters, but the number in nature must be many thousands. Our knowledge of gene function is growing but is not keeping up with the discovery of new sequences and structures. The aim is to determine structure and functio ....Synthesis and assembly of bacterial repeat unit polysaccharides. Bacteria make an enormous range of surface polysaccharides. The complexity was first appreciated as antigenic diversity, but we now have hundreds of chemical structures and perhaps a hundred sequences of their gene clusters, but the number in nature must be many thousands. Our knowledge of gene function is growing but is not keeping up with the discovery of new sequences and structures. The aim is to determine structure and function of key O antigen processing genes and the functions of a range of glycosyl transferases, and to use the information to generate novel gene clusters to synthesise novel polysaccharidesRead moreRead less
A sustainable cellular factory for the production of antibiotics by photosynthetic bacteria. The range and rate of natural product discovery is the limiting factor in developing new pharmaceuticals. Traditional methods for the screening of these compounds or for their chemical synthesis are rapidly becoming inadequate as an increasing number of specific therapies, for cancers and infectious diseases for instance, are required. The research proposed will enable the design and production of "unnat ....A sustainable cellular factory for the production of antibiotics by photosynthetic bacteria. The range and rate of natural product discovery is the limiting factor in developing new pharmaceuticals. Traditional methods for the screening of these compounds or for their chemical synthesis are rapidly becoming inadequate as an increasing number of specific therapies, for cancers and infectious diseases for instance, are required. The research proposed will enable the design and production of "unnatural" products, including novel antibiotics, via combinatorial biosynthesis in photosynthetic microorgansims. The outcomes include graduate student training and Australian innovation in an enormous global market that is awaiting the next generation of medicines and associated pharmaceutical production technologies.Read moreRead less
Improving the sustainability of Australia's water resources: an effective approach for diagnosing and treating foulants on water recycling membrane filters. By determining ways to diagnose and treat fouling problems we will have effectively solved a critical problem in the water recycling industry. By creating more efficient and sustainable ways of using water, we will transform the effectiveness of a wealth of Australian industries that increasingly rely on the efficient use of water (e.g. mini ....Improving the sustainability of Australia's water resources: an effective approach for diagnosing and treating foulants on water recycling membrane filters. By determining ways to diagnose and treat fouling problems we will have effectively solved a critical problem in the water recycling industry. By creating more efficient and sustainable ways of using water, we will transform the effectiveness of a wealth of Australian industries that increasingly rely on the efficient use of water (e.g. mining, agriculture, textiles, energy). By reducing the demand for water (by effectively recycling it), and the energy requirements (by efficiently recycling it), we will increase national wealth and provide significant social and environmental benefits to all Australians.Read moreRead less
Enhanced biocatalysis in organic solvents for pharmaceutical biotransformation. Enzymes such as hydrolases play an important role in biotechnology because of their extreme versatility with respect to substrate specificity and stereoselectivity. The use of lipases as catalysts for optical isomer-specific organic reactions is often limited by unacceptably low enantioselectivities. We will investigate recombinant enzymes cloned from thermophilic lipolytic bacteria for synthetic reactions in orga ....Enhanced biocatalysis in organic solvents for pharmaceutical biotransformation. Enzymes such as hydrolases play an important role in biotechnology because of their extreme versatility with respect to substrate specificity and stereoselectivity. The use of lipases as catalysts for optical isomer-specific organic reactions is often limited by unacceptably low enantioselectivities. We will investigate recombinant enzymes cloned from thermophilic lipolytic bacteria for synthetic reactions in organic solvents, especially chiral resolution of mixtures in the production of pharmaceutical intermediates. Genetic improvement of lipase enantiospecificity and regioselectivity will be achieved using in vitro evolution by recombination and screening. The outcome will be cost-effective production superior biocatalysts with specifically enhanced regiospecific, enantioselective and hydrolytic characteristics.
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