A5069632365- Genomics and Phylogenetic Studies
- Advanced Electron Microscopy Techniques and Applications
- Bacteriophages and microbial interactions
- Microbial Community Ecology and Physiology
- Bacterial Genetics and Biotechnology
- Protist diversity and phylogeny
- Photosynthetic Processes and Mechanisms
- Inorganic Chemistry and Materials
- RNA and protein synthesis mechanisms
- Mycobacterium research and diagnosis
- Tuberculosis Research and Epidemiology
- Nitric Oxide and Endothelin Effects
- Chromium effects and bioremediation
- Glutathione Transferases and Polymorphisms
- Chemical Reactions and Isotopes
- Pharmacogenetics and Drug Metabolism
- Wastewater Treatment and Nitrogen Removal
- Methane Hydrates and Related Phenomena
- Metalloenzymes and iron-sulfur proteins
- Amino Acid Enzymes and Metabolism
- Microbial Fuel Cells and Bioremediation
- Ammonia Synthesis and Nitrogen Reduction
- Mass Spectrometry Techniques and Applications
- Metal-Catalyzed Oxygenation Mechanisms
- Polysaccharides and Plant Cell Walls
University of British Columbia
2007-2025
California Institute of Technology
2010-2021
Université de Montréal
2016-2020
National Institutes of Health
2009
Rosalind Franklin University of Medicine and Science
2009
University of Wisconsin–Madison
2009
National Cancer Institute
2009
Center for Cancer Research
2009
Weizmann Institute of Science
2006
Leiden University
2006
Chemoreceptors are key components of the high-performance signal transduction system that controls bacterial chemotaxis. typically localized in a cluster at cell pole, where interactions among receptors thought to contribute high sensitivity, wide dynamic range, and precise adaptation signaling system. Previous structural genomic studies have produced conflicting models, however, for arrangement chemoreceptors clusters. Using whole-cell electron cryo-tomography, here we show different...
A copper-nitrosyl intermediate forms during the catalytic cycle of nitrite reductase, enzyme that mediates committed step in bacterial denitrification. The crystal structure a type 2 complex reductase reveals an unprecedented side-on binding mode which nitrogen and oxygen atoms are nearly equidistant from copper cofactor. Comparison this with refined nitrite-bound explains how coordination can change between copper-oxygen copper-nitrogen catalysis. expands possibilities for nitric oxide...
Significance Quiescent bacteria are intrinsically resistant to antibiotics and the host immune response. A conserved bacterial starvation survival response is consumption of ATP make an inorganic polymer, polyphosphate (polyP), which then forms granule superstructures. PolyP granules occur in all three domains life, yet how why cells form these structures poorly understood. Through high-resolution spatiotemporal characterization de novo genesis, we find that polyP synthesis required for...
Summary While vegetative B acillus subtilis cells and mature spores are both surrounded by a thick layer of peptidoglycan ( PG , polymer glycan strands cross‐linked peptide bridges), it has remained unclear whether surrounds prespores during engulfment. To clarify this issue, we generated slender Δ ponA mutant that enabled high‐resolution electron cryotomographic imaging. Three‐dimensional reconstructions whole in near‐native states revealed thin ‐like extending from the lateral cell wall...
is an atypical diderm bacterium with a remarkable ability to tolerate various environmental stresses, due in part its complex cell envelope encapsulated within hyperstable surface layer (S-layer). Despite decades of research on this envelope, atomic structural details the S-layer have remained obscure. In study, we report electron cryomicroscopy structure
Mycobacterium tuberculosis (Mtb) and Rhodococcus jostii RHA1 have similar cholesterol catabolic pathways. This pathway contributes to the pathogenicity of Mtb. The hsaAB genes been predicted encode oxygenase reductase, respectively, a flavin-dependent mono-oxygenase that hydroxylates 3-hydroxy-9,10-seconandrost-1,3,5(10)-triene-9,17-dione (3-HSA) catechol. An hsaA deletion mutant did not grow on but transformed latter 3-HSA related metabolites in which each two keto groups was reduced:...
Mycobacteria are well known for their taxonomic diversity, impact on global health, and atypical cell wall envelope. In addition to a cytoplasmic membrane peptidoglycan layer, the envelope of members order Corynebacteriales, which include Mycobacterium tuberculosis, also have an arabinogalactan layer connecting outer membrane, so-called "mycomembrane". This unusual composition mycobacteria is prime importance several physiological processes such as protection from external stresses...
Studying bacterial cell envelope architecture with electron microscopy is challenging due to the poor preservation of microbial ultrastructure traditional methods. Here, we established and validated a super-resolution cryo-correlative light (cryo-CLEM) method, combined it cryo-focused ion beam (cryo-FIB) milling scanning (SEM) volume imaging structurally characterize bacterium Deinococcus radiodurans. Subsequent cryo-electron tomography (cryo-ET) revealed an unusual diderm thick layer...
A lanthanide complex, named CLaNP (caged NMR probe) has been developed for the characterisation of proteins by paramagnetic spectroscopy. The probe consists a chelated derivative DTPA (diethylenetriaminepentaacetic acid) with two thiol reactive functional groups. molecule is attached to protein engineered, surface-exposed, Cys residues in bidentate manner. This drastically limits dynamics metal relative and enables measurements pseudocontact shifts. spectroscopy experiments on diamagnetic...
Background Bacterial outer membrane vesicles (OMV) are packets of periplasmic material that, via the proteins and other molecules they contain, project metabolic function into environment. While OMV production is widespread in proteobacteria, have been extensively studied only pathogens, which inhabit fully hydrated environments. However, many (arguably most) bacterial habitats, such as soil, partially hydrated. In latter, water characteristically distributed films on soil particles that...
ABSTRACT Electron cryotomography (ECT) can reveal the native structure and arrangement of macromolecular complexes inside intact cells. This technique has greatly advanced our understanding ultrastructure bacterial We now view bacteria as structurally complex assemblies machines rather than undifferentiated bags enzymes. To date, group applied ECT to nearly 90 different species, collecting more 15,000 cryotomograms. In addition known structures, we have observed, knowledge, several...
In the deep ocean, conversion of methane into derived carbon and energy drives establishment diverse faunal communities. Yet specific biological mechanisms underlying introduction methane-derived food web remain poorly described, due to a lack cultured representative deep-sea methanotrophic prokaryotes. Here, response aerobic methanotroph Methyloprofundus sedimenti starvation recovery was characterized. By combining lipid analysis, RNA electron cryotomography, it shown that M. undergoes...
This work’s relevance for the microbiology community is twofold. It delivers first time high-resolution near-native snapshots of Gluconacetobacter spp. (previously Komagataeibacter spp.) in process cellulose ribbon synthesis, their native biofilm environment.
(MABS) is a pathogenic bacterium that can cause severe lung infections, particularly in individuals with cystic fibrosis. MABS colonies exhibit either smooth (S) or rough (R) morphotype, influenced by the presence absence of glycopeptidolipids (GPLs) on their surface, respectively. Despite clinical significance these morphotypes, relationship between GPL levels, morphotype and pathogenesis infections remains poorly understood.
Using electron cryotomography, we show that the Gram-negative sporulating bacterium Acetonema longum synthesizes high-density storage granules at leading edges of engulfing membranes. The appear in prespore and increase size number as engulfment proceeds. Typically, a cluster 8 to 12 closely associates with inner spore membrane ultimately accounts for ∼7% total volume mature spores. Energy-dispersive X-ray spectroscopy (EDX) analyses contain high levels phosphorus, oxygen, magnesium...