A5084998185- Enzyme Production and Characterization
- Probiotics and Fermented Foods
- Microbial Metabolites in Food Biotechnology
- Glycosylation and Glycoproteins Research
- Carbohydrate Chemistry and Synthesis
- Gut microbiota and health
- Polysaccharides and Plant Cell Walls
- Biofuel production and bioconversion
- Biopolymer Synthesis and Applications
- Legume Nitrogen Fixing Symbiosis
- Proteoglycans and glycosaminoglycans research
- Photosynthetic Processes and Mechanisms
- Escherichia coli research studies
- Digestive system and related health
- Microbial Community Ecology and Physiology
- IL-33, ST2, and ILC Pathways
- Helicobacter pylori-related gastroenterology studies
- bioluminescence and chemiluminescence research
- Metalloenzymes and iron-sulfur proteins
- Hemoglobin structure and function
- Invertebrate Taxonomy and Ecology
- Fibroblast Growth Factor Research
- Aquatic Ecosystems and Phytoplankton Dynamics
- Fluorine in Organic Chemistry
- Spider Taxonomy and Behavior Studies
Newcastle University
2013-2024
Newcastle upon Tyne Hospital
2015
University of Exeter
2010
University of York
2005
Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by enzymes, but processed absorbable short chain fatty acids bacteria. The Bacteroidetes, one of two dominant bacterial phyla adult gut, possess broad glycan-degrading abilities. species use a series membrane protein complexes, termed Sus-like systems, for catabolism many carbohydrates....
Abstract The structure of the human gut microbiota is controlled primarily through degradation complex dietary carbohydrates, but extent to which carbohydrate breakdown products are shared between members unclear. We show here, using xylan as a model, that sharing carbohydrates by key microbiota, such Bacteroides ovatus , dependent on complexity target glycan. Characterization extensive degrading apparatus expressed B. reveals polysaccharide significantly more than previous models suggested,...
Significance The major nutrients available to the human microbiota are complex carbohydrates. Host glycans important this microbial community, particularly when dietary carbohydrates scarce. host heparin and heparan sulfate high-priority for Bacteroides thetaiotaomicron , a member of microbiota. degradation these is challenging, reflecting their highly variable sulfation patterns. How bacteria have adapted depolymerize myriad substructures class glycosaminoglycan unknown. Here, we show how...
Interactions between the host and its microbiota are of mutual benefit promote health. Complex molecular pathways underlie this dialog, but identity microbe-derived molecules that mediate mutualistic state remains elusive. Helicobacter hepaticus is a member mouse intestinal tolerated by host. In absence an intact IL-10 signaling, H. induces IL-23-driven inflammatory response in intestine. Here we investigate interactions immune cells may mutualism, molecule(s) involved. Our results show...
Signaling across the membrane in response to extracellular stimuli is essential for survival of all cells. In bacteria, responses environmental changes are predominantly mediated by two-component systems, which typically composed a membrane-spanning sensor histidine kinase and cytoplasmic regulator. human gut symbiont Bacteroides thetaiotaomicron , hybrid systems key part bacterium’s ability sense degrade complex carbohydrates gut. Here, we identify activating ligand system, BT4663, controls...
Glycans are major nutrients available to the human gut microbiota. The Bacteroides generalist glycan degraders, and this function is mediated largely by polysaccharide utilization loci (PULs). genomes of several species contain a PUL, PUL1,6-β-glucan, that was predicted target mixed linked plant 1,3;1,4-β-glucans. To test hypothesis we characterized proteins encoded locus in thetaiotaomicron, member We show here PUL1,6-β-glucan does not orchestrate degradation but targets fungal cell wall...
Abstract Bacterial cell growth and division require the coordinated action of enzymes that synthesize degrade wall polymers. Here, we identify cleave d -arabinan core arabinogalactan, an unusual component Mycobacterium tuberculosis other mycobacteria. We screened 14 human gut-derived Bacteroidetes for arabinogalactan-degrading activities identified four families glycoside hydrolases with activity against or -galactan components arabinogalactan. Using one these isolates exo-...
Summary Cells respond to nutrient availability by expressing catabolic genes. We report that the regulator controlling utilization of chondroitin sulphate ( CS ) in mammalian gut symbiont B acteroides thetaiotaomicron is activated an intermediate breakdown rather than itself. determine rate‐determining enzyme responsible for degrading this and establish levels increase 100‐fold, whereas those remain constant upon exposure . Because compete intermediate, tunes transcription genes rate. This...
The complex carbohydrates accessible to the distal gut microbiota (DGM) are key drivers in determining structure of this ecosystem. Typically, plant cell wall polysaccharides and recalcitrant starch (i.e. dietary fiber), addition host glycans considered primary nutrients for DGM; however, we recently demonstrated that α-mannans, highly branched decorate surface yeast, also several members Bacteroides spp. This relationship suggests advent yeast contemporary food technologies colonization...
Mannosidases catalyze the hydrolysis of a diverse range polysaccharides and glycoconjugates, various sequence-based mannosidase families have evolved ingenious strategies to overcome stereoelectronic challenges mannoside chemistry. Using combination computational chemistry, inhibitor design synthesis, X-ray crystallography inhibitor/enzyme complexes, it is demonstrated that mannoimidazole-type inhibitors are energetically poised report faithfully on transition-state conformation, provide...
Selenate reductase (SER) from Thauera selenatis is a periplasmic enzyme that has been classified as type II molybdoenzyme. The comprises three subunits SerABC, where SerC an unusual b-heme cytochrome. In the present work spectropotentiometric characterization of component and identification redox partners to SER are reported. mid-point potential was determined by optical titration (Em + 234 ± 10 mV). A profile c-type cytochromes expressed in T. under selenate respiring conditions undertaken....
The depolymerization of complex glycans is an important biological process that considerable interest to environmentally relevant industries. β-Mannose a major component plant structural polysaccharides and eukaryotic N-glycans. These linkages are primarily cleaved by glycoside hydrolases, although recently, family phosphorylases, GH130, have also been shown target β-1,2- β-1,4-mannosidic linkages. In these bond cleavage was mediated single displacement reaction in which phosphate functions...
Abstract Virulence and metabolism are often interlinked to control the expression of essential colonisation factors in response host-associated signals. Here, we identified an uncharacterised transporter dietary monosaccharide ʟ-arabinose that is widely encoded by zoonotic pathogen enterohaemorrhagic Escherichia coli (EHEC), required for full competitive fitness mouse gut highly expressed during human infection. Discovery this suggested EHEC strains have enhanced ability scavenge therefore...
Mycobacterial glycolipids are important cell envelope structures that drive host-pathogen interactions. Arguably, the most lipoarabinomannan (LAM) and its precursor, lipomannan (LM), which trafficked from bacterium to host via unknown mechanisms. Arabinomannan is thought be a capsular derivative of these molecules, lacking lipid anchor. However, mechanism by this material generated has yet elucidated. Here, we describe identification glycoside hydrolase family 76 enzyme term LamH (Rv0365c in...
Abstract Mannosidases catalyze the hydrolysis of a diverse range polysaccharides and glycoconjugates, various sequence‐based mannosidase families have evolved ingenious strategies to overcome stereoelectronic challenges mannoside chemistry. Using combination computational chemistry, inhibitor design synthesis, X‐ray crystallography inhibitor/enzyme complexes, it is demonstrated that mannoimidazole‐type inhibitors are energetically poised report faithfully on transition‐state conformation,...
Cytochrome c′, a c-type cytochrome with unique spectroscopic and magnetic properties, has been characterized in variety of denitrifying photosynthetic bacteria. c′ role defence and/or removal NO but the mechanism action is not clear. To examine function from Neisseria meningitidis, protein was purified after heterologous overexpression Escherichia coli. The electronic spectra oxidized demonstrated pH-dependent transition (over pH range 6–10) typical known c′-type cytochromes. Interestingly,...