A5021125678- Connexins and lens biology
- HIV Research and Treatment
- RNA and protein synthesis mechanisms
- HIV/AIDS drug development and treatment
- Enzyme Structure and Function
- Protein Structure and Dynamics
- Ion channel regulation and function
- RNA modifications and cancer
- Advanced Electron Microscopy Techniques and Applications
- Mass Spectrometry Techniques and Applications
- Lipid Membrane Structure and Behavior
- Receptor Mechanisms and Signaling
- Nicotinic Acetylcholine Receptors Study
- Electron and X-Ray Spectroscopy Techniques
- Porphyrin Metabolism and Disorders
- Collagen: Extraction and Characterization
- Adenosine and Purinergic Signaling
- Genomics and Phylogenetic Studies
- Cell Adhesion Molecules Research
- Neuroscience and Neuropharmacology Research
- Iron Metabolism and Disorders
- Mitochondrial Function and Pathology
- Neuropeptides and Animal Physiology
- Chemical Synthesis and Analysis
- Nuclear Structure and Function
University of Virginia
2016-2025
Dalian Medical University
2016
Washington University in St. Louis
2016
Universidade Federal do Espírito Santo
2016
University of Montana
2013
University of California, San Diego
2013
La Jolla Institute for Immunology
2013
Abstract Our understanding of protein synthesis has been conceptualised around the structure and function bacterial ribosome. This complex macromolecular machine is target important antimicrobial drugs, an integral line defence against infectious diseases. Here, we describe how open access to cryo-electron microscopy facilities combined with bespoke user support enabled structural determination translating ribosome from Escherichia coli at 1.55 Å resolution. The obtained structures allow for...
In Gram-negative bacteria, the import of essential micronutrients across outer membrane requires a transporter, an electrochemical gradient protons inner membrane, and protein complex (ExbB, ExbD, TonB) that couples proton-motive force to transporter. The TonB binds directly conserved region, called Ton-box, We solved structure cobalamin transporter BtuB in with C-terminal domain TonB. contrast its conformations absence TonB, Ton-box forms β strand is recruited existing sheet which...
Abstract Gap junction channels mediate intercellular signalling that is crucial in tissue development, homeostasis and pathologic states such as cardiac arrhythmias, cancer trauma. To explore the mechanism by which Ca 2+ blocks communication during injury, we determined X-ray crystal structures of human Cx26 gap channel with without bound . The two were nearly identical, ruling out both a large-scale structural change local steric constriction pore. coordination sites reside at interfaces...
Virus assembly and maturation proceed through the programmed operation of molecular switches, which trigger both local global structural rearrangements to produce infectious particles. HIV-1 contains an switch that spans C-terminal domain (CTD) capsid (CA) region first spacer peptide (SP1) precursor protein, Gag. The crystal structure CTD-SP1 Gag fragment is a goblet-shaped hexamer in cup comprises CTD ensuing type II β-turn, stem 6-helix bundle. β-turn critical for immature virus bundle...
Abstract We propose the concept of universal fiducials based on a set pre-made semi-synthetic antibodies (sABs) generated by customized phage display selections against fusion protein BRIL, an engineered variant apocytochrome b562a. These sABs can bind to BRIL fused either into loops or termini different GPCRs, ion channels, receptors and transporters without disrupting their structure. A crystal structure in complex with affinity-matured sAB (BAG2) that bound all systems tested delineates...
HIV-1 protease (PR) cleavage of the Gag polyprotein triggers assembly mature, infectious particles. Final occurs at junction helix between capsid protein CA and SP1 spacer peptide. Here we used MicroED to delineate binding interactions maturation inhibitor bevirimat (BVM) using very thin frozen-hydrated, 3D microcrystals a CTD-SP1 construct with without bound BVM. The 2.9-Å structure revealed that single BVM molecule stabilizes six-helix bundle via both electrostatic dimethylsuccinyl moiety...
Abstract The host proteins SERINC3 and SERINC5 are HIV-1 restriction factors that reduce infectivity when incorporated into the viral envelope. accessory protein Nef abrogates incorporation of SERINCs via binding to intracellular loop 4 (ICL4). Here, we determine cryoEM maps full-length human an ICL4 deletion construct, which reveal hSERINC3 is comprised two α-helical bundles connected by a ~ 40-residue, highly tilted, “crossmember” helix. design resembles non-ATP-dependent lipid...
Many members of the AAA+ ATPase family function as hexamers that unfold their protein substrates. These AAA unfoldases include spastin, which plays a critical role in architecture eukaryotic cells by driving remodeling and severing microtubules, are cytoskeletal polymers tubulin subunits. Here, we demonstrate human spastin binds weakly to unmodified peptides from C-terminal segment α1A/B. A peptide comprising alternating glutamate tyrosine residues more tightly, is consistent with known...
Gap junction channels (GJCs) mediate intercellular communication and are gated by numerous conditions such as pH. The electron cryomicroscopy (cryo-EM) structure of Cx26 GJC at physiological pH recapitulates previous structures in lipid bilayers. At 6.4, we identify two conformational states, one resembling the open physiological-pH a closed conformation that displays six threads density, join to form pore-occluding density. Crosslinking hydrogen-deuterium exchange mass spectrometry reveal...
Neuronal nuclei are normally smoothly surfaced. In Alzheimer's disease (AD) and other tauopathies, though, they often develop invaginations. We investigated mechanisms functional consequences of neuronal nuclear invagination in tauopathies.
Collagens are ubiquitous in biology: functioning as the backbone of extracellular matrix, forming primary structural components key immune system complexes, and fulfilling numerous other roles a variety systems. Despite this, there is limited understanding how triple helices, basic collagen units, pack into collagenous assemblies. Here we use peptide self-assembly to design assemblies based on C1q collagen-like region. Using cryo-EM solved structure one assembly 3.5 Å resolution built an...
The ability of hemoglobin to scavenge the potent vasodilator nitric oxide (NO) in blood has been well established as a mechanism vascular tone homeostasis. In endothelial cells, alpha chain (hereafter, globin) and NO synthase form macromolecular complex, providing sink for directly adjacent production source. We have developed an globin mimetic peptide (named HbαX) that displaces endogenous increases bioavailable vasodilation. Here we show that, vivo, HbαX administration capillary...
The molecular nature of the structure responsible for proton sensitivity in KcsA has been identified as a charge cluster that surrounds inner helical bundle gate. Here, we show this sensor can be modified to engineer constitutively open form KcsA, amenable functional, spectroscopic and structural analyses. By combining neutralizations all acidic basic residues at positions 25, 117–122 124 (but not E118), mutant is generated displays channel activity up pH 9. revealed full opening appears...
The assembly and maturation of human immunodeficiency virus type 1 (HIV-1) require proteolytic cleavage the Gag polyprotein. rate-limiting step resides at junction between capsid protein CA spacer peptide 1, which assembles as a six-helix bundle (6HB). Bevirimat (BVM), first-in-class inhibitor drug, targets 6HB impedes cleavage, yet molecular mechanisms its activity, relatedly, escape mutant viruses, remain unclear. Here, we employed extensive dynamics (MD) simulations free energy...
Allosteric enhancers of the adenosine A<sub>1</sub> receptor amplify signaling by orthosteric agonists. are appealing drug candidates because their activity requires that site be occupied an agonist, thereby conferring specificity to stressed or injured tissues produce adenosine. To explore mechanism allosteric enhancer activity, we examined action on several constructs, including (1) species variants, (2) chimeras, (3) alanine scanning mutants, and (4) site-specific mutants. These findings...
Abstract Adenosine A2A receptors (A2AAR) evoke pleiotropic intracellular signaling events via activation of the stimulatory heterotrimeric G protein, Gs. Here, we used cryoEM to solve agonist-bound structure A2AAR in a complex with full-length Gs alpha and Gbeta4gamma2. The orthosteric binding site A2AAR-Gs alpha:beta4gamma2 was similar other structures A2AAR, or without Unexpectedly, solvent accessible surface area within interior substantially larger for Gbeta4 versus closest analog,...
Lanthanides can contribute a large anomalous component to X-ray scattering when present and ordered in target crystal. This signal is useful source of phase information crystallographic studies biological macromolecules. Thiol-reactive lanthanide chelates were tested as means incorporation lanthanides into protein crystals. Two compounds, each capable being loaded with choice, synthesized: diethylenetriaminepentaacetic 3-(2-pyridyldithio)propionyl hydrazide (DTPA-PDPH)...
Cell survival under nutrient-deprived conditions relies on cells' ability to adapt their organelles and rewire metabolic pathways. In yeast, glucose depletion induces a stress response mediated by mitochondrial fragmentation sequestration of cytosolic ribosomes mitochondria. This cellular adaptation promotes harsh environmental conditions; however, the underlying mechanism this remains unknown. Here, we demonstrate that upon protein synthesis is halted. Cryo-electron microscopy structure...
YadQ of Escherichia coli is a homolog the mammalian chloride channels ClC family. The yadQ gene was cloned as fusion protein with hexahistidine tag and tobacco etch virus protease site for removal tag. expressed in membrane E. extracted decylmaltoside. Purification achieved by metal affinity chromatography followed cation exchange. Circular dichroism revealed high α‐helical content. Size exclusion suggests that forms dimers. similarity primary, secondary, quaternary structure ability to...