Molecular mechanisms of catalysis and the basis of substrate specificity in polysaccharide hydrolases. Reaction intermediates along hydrolytic pathways and molecular determinants of substrate specificity of barley B-glucan exo- and endohydrolases will be defined using crystallographic and kinetic analyses. These enzymes are of central importance in cell wall metabolism during development of higher plants, and in plant-pathogen interactions. Realization of the project objectives will not only pro ....Molecular mechanisms of catalysis and the basis of substrate specificity in polysaccharide hydrolases. Reaction intermediates along hydrolytic pathways and molecular determinants of substrate specificity of barley B-glucan exo- and endohydrolases will be defined using crystallographic and kinetic analyses. These enzymes are of central importance in cell wall metabolism during development of higher plants, and in plant-pathogen interactions. Realization of the project objectives will not only provide fundamental information on catalytic mechanisms, but will also provide opportunities to manipulate enzyme specificity. Further, site-directed mutagenesis of the enzymes will be used to generate glycosynthases, which will be evaluated for their ability to synthesise novel oligosaccharide and polysaccharide products, some of which might show immunomodulating activity.Read moreRead less
The regulation of signalling molecules in Saccharomyces Cerevisiae by inositol polyphosphate 5-phosphatases. Phosphoinositide signalling molecules regulate the actin cytoskeleton, secretion, vesicular trafficking and cell growth and death. We have identified, cloned and characterised a family of signal terminating enzymes called inositol polyphosphate 5-phosphatases (5-phosphatases) that regulate phosphoinositide signalling molecules. We have cloned and characterised four distinct 5-phosphatases ....The regulation of signalling molecules in Saccharomyces Cerevisiae by inositol polyphosphate 5-phosphatases. Phosphoinositide signalling molecules regulate the actin cytoskeleton, secretion, vesicular trafficking and cell growth and death. We have identified, cloned and characterised a family of signal terminating enzymes called inositol polyphosphate 5-phosphatases (5-phosphatases) that regulate phosphoinositide signalling molecules. We have cloned and characterised four distinct 5-phosphatases in the yeast Saccharomyces Cerevisiae and demonstrated by both deletion and overexpression studies that these enzymes regulate the actin cytoskeleton, endocytosis and secretion. This research proposal aims to investigate the signalling complexes the 5-phosphatases form with specific actin binding and or regulatory proteins, investigate the complex interactions of phosphoinositide lipid phosphatases and the roles they play in regulating secretion from the endoplasmic reticulum and finally characterize a novel 5-phosphatase that we have recently identified. Collectively the outcome of these studies will provide novel information about the functionallly significant signalling pathways regulated by this important enzyme family.Read moreRead less
The role of PtdIns(4,5)P2 in cellular responses in Saccharomyces cerevisiae. This grant application falls under the criteria of frontier technologies in genomics/phenomics and complex systems. We are characterizing a highly conserved network of signaling molecules regulated by complex large families of enzymes that regulate the bending of membranes, and cellular events including cell division in plants, yeast and mammalian cells. We have developed cutting edge novel technologies to localize sign ....The role of PtdIns(4,5)P2 in cellular responses in Saccharomyces cerevisiae. This grant application falls under the criteria of frontier technologies in genomics/phenomics and complex systems. We are characterizing a highly conserved network of signaling molecules regulated by complex large families of enzymes that regulate the bending of membranes, and cellular events including cell division in plants, yeast and mammalian cells. We have developed cutting edge novel technologies to localize signaling on specific intracellular membranes and visualise the role cellular lipids play in forming tubules in cells. This project will result in the presentation of Australian research at international forums and support the training of PhD students.Read moreRead less
The design of targetable epigenetic modifiers. The project aims to engineer enzymes as valuable tools for understanding gene expression mechanisms and potentially a technology for altering gene expression in plants, animals or humans in a targetable manner. The genetic information encoded in the DNA of all complex organisms has been shown to be augmented by decorations on both DNA and the histone proteins that package DNA. This so-called epigenetic information is important but not well understoo ....The design of targetable epigenetic modifiers. The project aims to engineer enzymes as valuable tools for understanding gene expression mechanisms and potentially a technology for altering gene expression in plants, animals or humans in a targetable manner. The genetic information encoded in the DNA of all complex organisms has been shown to be augmented by decorations on both DNA and the histone proteins that package DNA. This so-called epigenetic information is important but not well understood. The project plans to design highly specific and targetable enzymes that can interrogate and manipulate epigenetic information in living cells. Understanding the regulation of gene expression and controlling the expression of chosen genes may form a foundation for applications in agriculture, biology and medicine.Read moreRead less
Structures and Functions of Bacterial Replisomal Proteins. DNA replication in all organisms requires many proteins to interact in a structure called the replisome. The bacterial replisome is assembled about the DnaB helicase, a motor protein that moves along DNA, separating the strands of duplex regions in its path. This project aims to develop understanding of the chemistry of DnaB and other replisomal proteins: their structures, how they work, and how they interact to assemble the replisome. T ....Structures and Functions of Bacterial Replisomal Proteins. DNA replication in all organisms requires many proteins to interact in a structure called the replisome. The bacterial replisome is assembled about the DnaB helicase, a motor protein that moves along DNA, separating the strands of duplex regions in its path. This project aims to develop understanding of the chemistry of DnaB and other replisomal proteins: their structures, how they work, and how they interact to assemble the replisome. This has the potential to lead to design of new antibacterial drugs.
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Exploring the catalytic role of the Rubisco small subunit: a new target for improving carbon dioxide-fixation in plants. This project uses new biotechnological tools to improve the performance of the photosynthetic protein Rubisco, the primary carbon dioxide-fixing enzyme in plants. By supercharging photosynthesis, this research will help to boost yield and reduce water and nitrogen use in crops.
Rubisco for all climates: unlocking the enzyme's structure-function relations for more efficient photosynthesis. This projects biotechnological research will identify structural features in the carbon dioxide (CO2)-capturing enzyme from plants that improve its performance, particularly at warmer temperatures. This knowledge is vital for predicting the influence of climate change on crop productivity and paving the way for supercharging photosynthesis to boost crop performance.
Biosynthetic LEGO: enzymatic redesign to produce new vancomycin analogues. This project aims to uncover the reengineering potential of the biosynthetic machinery that produces glycopeptide antibiotics by advancing our understanding of how the core peptide production line functions. Natural product biosynthesis often produces complex peptide structures, with one important example being the glycopeptide antibiotics. This project expects to generate new knowledge about enzymatic peptide biosynthesi ....Biosynthetic LEGO: enzymatic redesign to produce new vancomycin analogues. This project aims to uncover the reengineering potential of the biosynthetic machinery that produces glycopeptide antibiotics by advancing our understanding of how the core peptide production line functions. Natural product biosynthesis often produces complex peptide structures, with one important example being the glycopeptide antibiotics. This project expects to generate new knowledge about enzymatic peptide biosynthesis using a highly interdisciplinary approach and previously developed tools. The anticipated outcomes of this project will be an enhanced understanding of how such complex peptide biosynthesis is performed, which is knowledge vital for future efforts to reengineer such biosynthetic peptide assembly lines as a series of modular LEGO blocks to produce new bioactive peptides.Read moreRead less
Angiogenic defects in mutant growth plate cartilage reveal new modulators of vascular invasion. Converting cartilage to bone requires blood vessel invasion from the bony interface. This project will test, in vitro and in vivo, the hypothesis that collagen fragments regulate blood vessel invasion into cartilage. This data will have implications for processes requiring new blood vessels such as bone growth, cancer, inflammation and ischemia.
Defining peptide structure and function: the shape of things to come. In this project we develop new and general ways of chemically defining the structure and function of natural peptides. This then provides a basis of potential therapies to treat a number of diseases currently confronting Australia's aging population, for example, cataract, Alzheimer's disease, cancer, and cardiovascular disease.