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-Structure paper
Title | Cryo-EM structure of SARS-CoV-2 ORF3a in lipid nanodiscs. |
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Journal, issue, pages | Nat Struct Mol Biol, Vol. 28, Issue 7, Page 573-582, Year 2021 |
Publish date | Jun 22, 2021 |
Authors | David M Kern / Ben Sorum / Sonali S Mali / Christopher M Hoel / Savitha Sridharan / Jonathan P Remis / Daniel B Toso / Abhay Kotecha / Diana M Bautista / Stephen G Brohawn / |
PubMed Abstract | SARS-CoV-2 ORF3a is a putative viral ion channel implicated in autophagy inhibition, inflammasome activation and apoptosis. 3a protein and anti-3a antibodies are found in infected patient tissues and ...SARS-CoV-2 ORF3a is a putative viral ion channel implicated in autophagy inhibition, inflammasome activation and apoptosis. 3a protein and anti-3a antibodies are found in infected patient tissues and plasma. Deletion of 3a in SARS-CoV-1 reduces viral titer and morbidity in mice, suggesting it could be an effective target for vaccines or therapeutics. Here, we present structures of SARS-CoV-2 3a determined by cryo-EM to 2.1-Å resolution. 3a adopts a new fold with a polar cavity that opens to the cytosol and membrane through separate water- and lipid-filled openings. Hydrophilic grooves along outer helices could form ion-conduction paths. Using electrophysiology and fluorescent ion imaging of 3a-reconstituted liposomes, we observe Ca-permeable, nonselective cation channel activity, identify mutations that alter ion permeability and discover polycationic inhibitors of 3a activity. 3a-like proteins are found across coronavirus lineages that infect bats and humans, suggesting that 3a-targeted approaches could treat COVID-19 and other coronavirus diseases. |
External links | Nat Struct Mol Biol / PubMed:34158638 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.08 - 6.5 Å |
Structure data | EMDB-22136, PDB-6xdc: EMDB-22138: EMDB-22139: EMDB-22898, PDB-7kjr: |
Chemicals | ChemComp-PEE: ChemComp-HOH: |
Source |
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Keywords | TRANSPORT PROTEIN / SARS-CoV-2 / coronavirus / viroporin / ion channel / VIRAL PROTEIN / membrane protein |