NMR Structural Characterization of SARS-CoV-2 ORF6 Reveals an N-Terminal Membrane Anchor
SARS-CoV-2, the virus responsible for the COVID-19 pandemic, encodes several accessory proteins, among which ORF6, a potent interferon inhibitor, is recognized as one of the most cytotoxic. Here, we investigated the structure, oligomeric state, and membrane interactions of ORF6 using NMR spectroscopy and molecular dynamics simulations. Using chemical-shift-ROSETTA, we show that ORF6 in proteoliposomes adopts a straight α-helical structure with an extended, rigid N-terminal part and flexible C-terminal residues. Cross-linking experiments indicate that ORF6 forms oligomers within lipid bilayers, and paramagnetic spin labeling suggests an antiparallel arrangement in its multimers. The amphipathic ORF6 helix establishes multiple contacts with the membrane surface with its N-terminal residues acting as membrane anchors. Our work demonstrates that ORF6 is an integral monotopic membrane protein and provides key insights into its conformation and the importance of the N-terminal region for the interaction with the membrane.
Authors
- Lauriane Lecoq (ORCID: https://orcid.org/0000-0002-5995-3733)
- Anja Böckmann (ORCID: https://orcid.org/0000-0001-8149-7941)
- Beate Bersch (ORCID: https://orcid.org/0000-0003-1138-4911)
- Jackson Crowley (ORCID: https://orcid.org/0000-0002-2997-4365)
- Gyula Pálfy (ORCID: https://orcid.org/0000-0003-1590-5331)
- Martí Ninot‐Pedrosa (ORCID: https://orcid.org/0000-0003-2851-9990)
- Marie‐Laure Fogeron (ORCID: https://orcid.org/0000-0002-2146-8740)
- Beat H. Meier (ORCID: https://orcid.org/0000-0002-9107-4464)
- Alexander B. Barnes (ORCID: https://orcid.org/0000-0003-3748-8508)
- Luca Monticelli (ORCID: https://orcid.org/0000-0002-6352-4595)
- Hafez Razmazma (ORCID: https://orcid.org/0000-0002-3534-3068)
- Bernhard Brutscher (ORCID: https://orcid.org/0000-0001-7652-7384)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- CEA Grenoble (FR)
- ETH Zurich (CH)
- Institut de Biologie Structurale (FR)
- Université Grenoble Alpes (FR)
Publication Details
- Journal
- Journal of the American Chemical Society
- Published
- 2025-05-15
- DOI
- https://doi.org/10.1021/jacs.4c17030
- Citations
- 2
- Primary Topic
- Bacteriophages and microbial interactions
- Type
- article
- Field-Weighted Citation Impact
- 3.43
Funders
- Fondation Innovations en Infectiologie
- Agence Nationale de la Recherche
- Institut National de la Santé et de la Recherche Médicale
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Fondation pour la Recherche Médicale