MiLoPYP: self-supervised molecular pattern mining and particle localization in situ Cryo-electron tomography (CET) allows the routine visualization of cellular landscapes in three dimensions at nanometer-range resolutions. When combined with single-particle tomography (SPT), it is possible to obtain near-atomic resolution structures of frequently occurring macromolecules within their native environment. Two outstanding challenges associated with CET/SPT are the automatic identification and…
Fab-dimerized glycan-reactive antibodies are a structural category of natural antibodies Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. We describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive neutralizing Abs in HIV-1 vaccinated and simian-HIV (SHIV)-infected…
Single-particle cryo-EM structure of a voltage-activated potassium channel in lipid nanodiscs The structure of a voltage-activated potassium channel in lipid nanodiscs solved using cryo-electron microscopy is similar to previous X-ray structures, and provides insights into the mechanism of C-type inactivation. eLife, 7:e37558, 2018.
Cryo-EM structure of human rhodopsin bound to an inhibitory G protein For the first time, scientists have visualized the interaction between two critical components of the body’s vast cellular communication network, a discovery that could lead to more effective medications with fewer side effects for conditions ranging from migraine to cancer. The near-atomic resolution images obtained, show a G-protein coupled…
Cryo-electron Microscopy Structures of Chimeric Hemagglutinin Displayed on a Universal Influenza Vaccine Candidate Chimeric hemagglutinin proteins are set to undergo human clinical trials as a universal influenza vaccine candidate, yet no structural information for these proteins is available. Using cryo-electron tomography, we report the first three-dimensional (3D) visualization of chimeric hemagglutinin proteins displayed on the surface of the influenza…
Cryo-EM Structures of the Magnesium Channel CorA Reveal Symmetry Break upon Gating Magnesium ions (Mg2+) play essential roles in all living organisms. Bacteria and other prokaryotes rely upon the Mg2+-dependent channel CorA, which is composed of five identical subunits (A-E), to obtain these ions from their surroundings. Studies of CorA showed that, in contrast to most ligand-gated ion channels,…
Structural Mechanism of Glutamate Receptor Activation and Desensitization Understanding the structural basis of the transition from closed to active and desensitized conformations is central to deciphering the function of ionotropic glutamate receptors NMDA receptors, AMPA receptors, delta receptors, and kainate receptors as mediators of excitatory synaptic transmission in the central nervous system. Ligand binding at the receptor's extracellular surface…
Prefusion Structure of Trimeric HIV-1 Envelope Glycoprotein Determined by Cryo-Electron Microscopy HIV-1 Env transitions from a closed to an open state upon binding to its cellular receptor. Single-particle cryo-EM analysis now reveals the closed state of the HIV-1 Env trimer at ~6-Å resolution, featuring three gp41 helices at the center of the trimer. These findings indicate that HIV-1 enters…
Molecular Architectures of Trimeric SIV and HIV-1 Envelope Glycoproteins on Intact Viruses: Strain-Dependent Variation in Quaternary Structure HIV and SIV contact and infect target T-cells following the binding of trimeric Env spikes displayed on the viral membrane with cellular receptors. The conformational changes in trimeric Env that are triggered by the interaction between trimeric Env and cell surface receptors…
Molecular Architecture of Native HIV-1 gp120 Trimers We determined the structure of the native gp120 coat protein of HIV by cryo-electron tomography and molecular modelling. Comparison of gp120 structures in an unbound state, bound to a neutralizing antibody and bound to CD4 cell surface protein provides insight into the conformational changes that occur during antibody neutralization and attachment to…
