Living on air: how do bacteria scavenge atmospheric trace gases? This project aims to determine the molecular and cellular basis of atmospheric trace gas oxidation by bacteria. Bacteria have a remarkable ability to adapt to resource limitation and environmental change by entering dormant states. Our research has shown they survive in this state by using atmospheric hydrogen and carbon monoxide as energy sources. This interdisciplinary project will determine how bacteria achieve this by elucidati ....Living on air: how do bacteria scavenge atmospheric trace gases? This project aims to determine the molecular and cellular basis of atmospheric trace gas oxidation by bacteria. Bacteria have a remarkable ability to adapt to resource limitation and environmental change by entering dormant states. Our research has shown they survive in this state by using atmospheric hydrogen and carbon monoxide as energy sources. This interdisciplinary project will determine how bacteria achieve this by elucidating the regulation, mechanism, and integration of the three uncharacterised enzymes that mediate this process. Outcomes and benefits include understanding of the processes that facilitate bacterial persistence, regulate atmospheric composition, and in turn support resilience of natural ecosystems.Read moreRead less
Dissociation of a Tetrameric Enzyme with Interface-Targeted Peptides. With antibiotic resistance on the rise, there is an urgent need to develop new antibiotics and an equally urgent need to characterise new antibiotic targets. One such target is dihydrodipicolinate synthase (DHDPS) which catalyses the critical step in lysine and cell wall biosynthesis in bacteria. This proposal aims to generate new drugs targeting DHDPS for effective and rapid treatment of bacterial infections, including gastro ....Dissociation of a Tetrameric Enzyme with Interface-Targeted Peptides. With antibiotic resistance on the rise, there is an urgent need to develop new antibiotics and an equally urgent need to characterise new antibiotic targets. One such target is dihydrodipicolinate synthase (DHDPS) which catalyses the critical step in lysine and cell wall biosynthesis in bacteria. This proposal aims to generate new drugs targeting DHDPS for effective and rapid treatment of bacterial infections, including gastroenteritis. Recent statistics show that over 5 million Australians suffer from gastroenteritis each year and hospitalisation for this infection is nearly seven times higher for indigenous than non-indigenous children. Accordingly, this research has the potential to assure a healthier future for millions of Australians.Read moreRead less
Structures to Solve Conflicts of DNA Replication and RNA Transcription. This project aims to understand how new DNA is made so quickly and without mistakes in cells that are about to divide, in spite of competition from other processes happening at the same time on the DNA that should stop or interfere with it, such as the synthesis of RNA. The project expects to use the latest available methods to uncover what the microscopic natural machines that make DNA and RNA look like, and how they compet ....Structures to Solve Conflicts of DNA Replication and RNA Transcription. This project aims to understand how new DNA is made so quickly and without mistakes in cells that are about to divide, in spite of competition from other processes happening at the same time on the DNA that should stop or interfere with it, such as the synthesis of RNA. The project expects to use the latest available methods to uncover what the microscopic natural machines that make DNA and RNA look like, and how they compete with each other for access to DNA. Potential outcomes include the identification of processes that can be compromised by small molecules that may be developed into new antibiotics. This would be of great benefit - new antibiotics are urgently needed as one approach to countering the threat of antimicrobial resistance.Read moreRead less
Investigation of a Novel Protein Implicated in Phosphate Metabolism in Bacteria. Phosphate is an important nutrient for all forms of life on Earth. A novel bacterial protein has been identified that appears to be important for the uptake or processing of phosphate, since mutants lacking the protein grow poorly inside certain cells of the human immune system (where phosphate levels are low) and in media containing low phosphate. The aims of this project are: to determine the role of the protein b ....Investigation of a Novel Protein Implicated in Phosphate Metabolism in Bacteria. Phosphate is an important nutrient for all forms of life on Earth. A novel bacterial protein has been identified that appears to be important for the uptake or processing of phosphate, since mutants lacking the protein grow poorly inside certain cells of the human immune system (where phosphate levels are low) and in media containing low phosphate. The aims of this project are: to determine the role of the protein by examining all phosphate containing molecules in our mutants; to determine its location in bacteria and functional domains; to identify other affected genes in our mutants; and, to find proteins that interact with this new protein. This project expects to demonstrate the importance of this protein in phosphate metabolism in bacteria.Read moreRead less
Molecular mechanisms of pilin glycosylation in Neisseria: a model system for protein glycosylation in bacteria. The disease causing bacteria Neisseria meningitidis and Neisseria gonorrhoeae are important human pathogens. Cell surface structures, called pili, are known to be important in allowing the bacteria to stick to host cells. Genetic and structural studies have identified that the protein subunits, which make up pili, are glycosylated - modified by the addition of sugars. Until recently ....Molecular mechanisms of pilin glycosylation in Neisseria: a model system for protein glycosylation in bacteria. The disease causing bacteria Neisseria meningitidis and Neisseria gonorrhoeae are important human pathogens. Cell surface structures, called pili, are known to be important in allowing the bacteria to stick to host cells. Genetic and structural studies have identified that the protein subunits, which make up pili, are glycosylated - modified by the addition of sugars. Until recently glycosylation of Gram-negative bacterial proteins was not thought to occur, however our recent work with these bacteria, and other groups studying Pseudomonas and Campylobacter, have shown that this process may be widespread. In our previous studies, we have identified and analysed a number of genes involved in pili glycosylation, in bacteria, which make known sugar structures. We have used this information to developed models for how the biochemistry and physiology of the glycosylation system may work. With a well-established structure and many genes already identified, glycosylation in Neisseria represents the best available model system to study this novel and important process. In the proposed study we describe experiments planned to test our models and reveal the molecular detail of this process. This study could lead to major advances in our understanding of this process and, when understood, may have future applications in biotechnology.Read moreRead less
The protein O-glycosylation pathway in Neisseria meningitidis. Neisseria meningitidis causes bacterial meningitis, a sudden and severe disease of particular concern to children in both the developed and developing worlds. This project will contribute to an understanding of how these bacteria evade the immune system by modifying the proteins displayed on their surface, which will help in the development of a vaccine.
Novel mechanisms of bacterial arsenic metabolism - arsenate reduction and arsenite oxidation. Novel arsenic metabolising bacteria (i.e., arsenate respiring and arsenite oxidising), which are both phylogenetically and physiologically unique, have been isolated from arsenic-contaminated areas in Australia. The arsenate respiring bacterium, Chrysiogenes arsenatis, is of particular interest as it is the only organism reported able to respire with arsenate using the respiratory substrate acetate as t ....Novel mechanisms of bacterial arsenic metabolism - arsenate reduction and arsenite oxidation. Novel arsenic metabolising bacteria (i.e., arsenate respiring and arsenite oxidising), which are both phylogenetically and physiologically unique, have been isolated from arsenic-contaminated areas in Australia. The arsenate respiring bacterium, Chrysiogenes arsenatis, is of particular interest as it is the only organism reported able to respire with arsenate using the respiratory substrate acetate as the electron donor. It is proposed that physiological, biochemical and molecular biological studies be carried out to better understand the mechanisms by which these organisms metabolise arsenic. The knowledge gained from these studies will have worldwide application in the development of an arsenic bioremediation system.Read moreRead less
A Unique Target in the Purine Biosynthesis of the Pathogen Helicobacter pylori. The uptake systems of purine and analogues of the human pathogen Helicobacter pylori will be characterised because they can be utilised to introduce cytotoxic compounds into the cells. The first step in de novo purine biosynthesis of the bacterium is catalysed by two different enzymes, which are components of other biosynthetic pathways. These unique properties make them excellent potential therapeutic targets. Their ....A Unique Target in the Purine Biosynthesis of the Pathogen Helicobacter pylori. The uptake systems of purine and analogues of the human pathogen Helicobacter pylori will be characterised because they can be utilised to introduce cytotoxic compounds into the cells. The first step in de novo purine biosynthesis of the bacterium is catalysed by two different enzymes, which are components of other biosynthetic pathways. These unique properties make them excellent potential therapeutic targets. Their individual combined activities in purine biosynthesis will be characterised in situ and in vitro. Isogenic mutants with inactivated genes encoding for these enzymes will be constructed to investigate their role in the survival of the organism.Read moreRead less