1mof

Structural highlights

Function

[ENV_MLVMS] The surface protein (SU) attaches the virus to the host cell by binding to its receptor. Interaction with HECT ubiquitin ligases activates a thiol in a CXXC motif of the C-terminal domain, where the other Cys residue participates in the formation of the intersubunit disulfide. The activated thiol will attack the disulfide and cause its isomerization into a disulfide isomer within the motif. This leads to SU displacement and TM refolding, and is thought to activate its fusogenic potential by unmasking its fusion peptide. Fusion occurs at the host cell plasma membrane.^[1] The transmembrane protein (TM) acts as a class I viral fusion protein. Under the current model, the protein has at least 3 conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes. Membranes fusion leads to delivery of the nucleocapsid into the cytoplasm (By similarity).

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

References

1. ↑ Wu SR, Sjoberg M, Wallin M, Lindqvist B, Ekstrom M, Hebert H, Koeck PJ, Garoff H. Turning of the receptor-binding domains opens up the murine leukaemia virus Env for membrane fusion. EMBO J. 2008 Oct 22;27(20):2799-808. doi: 10.1038/emboj.2008.187. Epub 2008 Sep, 18. PMID:18800055 doi:http://dx.doi.org/10.1038/emboj.2008.187
2. ↑ Fass D, Harrison SC, Kim PS. Retrovirus envelope domain at 1.7 angstrom resolution. Nat Struct Biol. 1996 May;3(5):465-9. PMID:8612078