A5044073683- ATP Synthase and ATPases Research
- Photosynthetic Processes and Mechanisms
- Advanced Electron Microscopy Techniques and Applications
- Mitochondrial Function and Pathology
- RNA and protein synthesis mechanisms
- Electron and X-Ray Spectroscopy Techniques
- Enzyme Structure and Function
- Bacterial Genetics and Biotechnology
- Biochemical and Molecular Research
- Tuberculosis Research and Epidemiology
- Metalloenzymes and iron-sulfur proteins
- RNA modifications and cancer
- Advanced X-ray Imaging Techniques
- Cellular transport and secretion
- Bacteriophages and microbial interactions
- Endoplasmic Reticulum Stress and Disease
- Malaria Research and Control
- Mycobacterium research and diagnosis
- Ubiquitin and proteasome pathways
- Drug Transport and Resistance Mechanisms
- Trypanosoma species research and implications
- Biochemical and Structural Characterization
- Protein Structure and Dynamics
- Lipid Membrane Structure and Behavior
- Antifungal resistance and susceptibility
Hospital for Sick Children
2016-2025
University of Toronto
2016-2025
SickKids Foundation
2015-2024
Canada Research Chairs
2011-2024
Great Ormond Street Hospital
2015-2023
University College London
2015-2023
The King's College
2020-2022
University of New Brunswick
2020
University of California System
2017
Ontario Institute for Cancer Research
2008
Adenosine triphosphate (ATP), the chemical energy currency of biology, is synthesized in eukaryotic cells primarily by mitochondrial ATP synthase. synthases operate a rotary catalytic mechanism where proton translocation through membrane-inserted FO region coupled to synthesis F1 via rotation central rotor subcomplex. We report here single particle electron cryomicroscopy (cryo-EM) analysis bovine Combining cryo-EM data with bioinformatic allowed us determine fold subunit, suggesting path...
The coronavirus S-protein mediates receptor binding and fusion of the viral host cell membranes. In HCoV-229E, its domain (RBD) shows extensive sequence variation but how function is maintained not understood. Reported are X-ray crystal structures Class III-V RBDs in complex with human aminopeptidase N (hAPN), as well electron cryomicroscopy structure 229E S-protein. show that common core interactions define specificity for hAPN peripheral RBD accommodated by loop plasticity. results provide...
Mitochondrial adenosine triphosphate (ATP) synthase produces the majority of ATP in eukaryotic cells, and its dimerization is necessary to create inner membrane folds, or cristae, characteristic mitochondria. Proton translocation through membrane-embedded FO region turns rotor that drives synthesis soluble F1 region. Although crystal structures have illustrated how this rotation leads synthesis, understanding proton has been impeded by lack an experimental atomic model for Using...
In neurons, the loading of neurotransmitters into synaptic vesicles uses energy from proton-pumping vesicular- or vacuolar-type adenosine triphosphatases (V-ATPases). These membrane protein complexes possess numerous subunit isoforms, which complicates their analysis. We isolated homogeneous rat brain V-ATPase through its interaction with SidK, a Legionella pneumophila effector protein. Cryo-electron microscopy allowed construction an atomic model, defining enzyme's ATP:proton ratio as 3:10...
ATP synthases produce from ADP and inorganic phosphate with energy a transmembrane proton motive force. Bacterial have been studied extensively because they are the simplest form of enzyme relative ease genetic manipulation these complexes. We expressed Bacillus PS3 synthase in Eschericia coli, purified it, imaged it by cryo-EM, allowing us to build atomic models complex three rotational states. The position subunit ε shows how is able inhibit hydrolysis while synthesis. architecture...
Venetoclax is a specific B cell lymphoma 2 (BCL-2) inhibitor with promising activity against acute myeloid leukemia (AML), but its clinical efficacy as single agent or in combination hypomethylating agents (HMAs), such azacitidine, hampered by intrinsic and acquired resistance. Here, we performed genome-wide CRISPR knockout screen found that inactivation of genes involved mitochondrial translation restored sensitivity to venetoclax resistant AML cells. Pharmacologic inhibition protein...
Intercellular communication in the nervous system occurs through release of neurotransmitters into synaptic cleft between neurons. In presynaptic neuron, proton pumping vesicular- or vacuolar-type ATPase (V-ATPase) powers neurotransmitter loading vesicles (SVs), with V 1 complex dissociating from membrane region enzyme before exocytosis. We isolated SVs rat brain using SidK, a V-ATPase–binding bacterial effector protein. Single-particle electron cryomicroscopy allowed high-resolution...
The comparison of a pair electron microscope images recorded at different specimen tilt angles provides powerful approach for evaluating the quality images, image-processing procedures, or three-dimensional structures. Here, we analyze tilt-pair from range specimens with symmetries and molecular masses show how analysis can produce valuable information not easily obtained otherwise. We that accuracy orientation determination individual single particles depends on mass, as expected...
CD22 maintains a baseline level of B-cell inhibition to keep humoral immunity in check. As B-cell-restricted antigen, is targeted therapies against dysregulated B cells that cause autoimmune diseases and blood cancers. Here we report the crystal structure human at 2.1 Å resolution, which reveals specificity for α2-6 sialic acid ligands dictated by pre-formed β-hairpin as unique mode recognition across acid-binding immunoglobulin-type lectins. The ectodomain adopts an extended conformation...
AAA+ unfoldases are thought to unfold substrate through the central pore of their hexameric structures, but how this process occurs is not known. VAT, Thermoplasma acidophilum homologue eukaryotic CDC48/p97, works in conjunction with proteasome degrade misfolded or damaged proteins. We show that presence ATP, VAT its regulatory N-terminal domains removed unfolds other complexes as substrate. captured images transient by electron cryomicroscopy (cryo-EM) reveal structure substrate-bound...
α-Catenin is an actin- and vinculin-binding protein that regulates cell-cell adhesion by interacting with cadherin receptors through β-catenin, but the mechanisms which it anchors cadherin-catenin complex to actin cytoskeleton at adherens junctions remain unclear. Here we determined crystal structures of αE-catenin in autoinhibited state actin-binding domain αN-catenin. Together small-angle x-ray scattering analysis full-length αN-catenin, deduced elongated multidomain assembly monomeric...