Extended Data Fig. 8: Lipid-bilayer bound SARS-CoV-2 ETM structure (PDB code: 7K3G) and its comparison with ETM structure solved in micelles and with other viroporin structures.

a, N-terminal top views of various residues in the ETM pentamer. Most residues are hydrophobic, including both pore-facing and lipid-facing residues. The most representative structure of the lowest-energy ensemble is shown. b, Top views of representative pore-facing residues in the lowest-energy ensemble. The structure distribution is likely due to a combination of the sparseness of experimental restraints and true protein conformational disorder. c, Comparison of the ERGIC-membrane bound ETM structure model (slate and red) and the LMPG-micelle-bound ETM structure model (gray and salmon)¹⁶. Side view depicts differences in helix orientation and helical bundle handedness, while top view shows differences in pore radii. d, Structural comparison of the pentameric ETM channel, the closed tetrameric influenza BM2 proton channel²⁵, and the pentameric HIV-1 Vpu channel³⁰. The ETM pentamer is longer and tighter than the BM2 and Vpu helical bundles.