Structural highlights
Function
[FUS_SV5] 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 plasma cell membrane fusion, the heptad repeat (HR) regions 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 plasma cell membranes. Directs fusion of viral and cellular membranes leading to delivery of the nucleocapsid into the cytoplasm. This fusion is pH independent and occurs directly at the outer cell membrane. The trimer of F1-F2 (F protein) probably interacts with HN at the virion surface. Upon HN binding to its cellular receptor, the hydrophobic fusion peptide is unmasked and interacts with the cellular membrane, inducing the fusion between cell and virion membranes. Later in infection, F proteins expressed at the plasma membrane of infected cells could mediate fusion with adjacent cells to form syncytia, a cytopathic effect that could lead to tissue necrosis (By similarity).
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Paramyxoviruses are responsible for significant human mortality and disease worldwide, but the molecular mechanisms underlying their entry into host cells remain poorly understood. We have solved the crystal structure of a fragment of the simian parainfluenza virus 5 fusion protein (SV5 F), revealing a 96 A long coiled coil surrounded by three antiparallel helices. This structure places the fusion and transmembrane anchor of SV5 F in close proximity with a large intervening domain at the opposite end of the coiled coil. Six amino acids, potentially part of the fusion peptide, form a segment of the central coiled coil, suggesting that this structure extends into the membrane. Deletion mutants of SV5 F indicate that putative flexible tethers between the coiled coil and the viral membrane are dispensable for fusion. The lack of flexible tethers may couple a final conformational change in the F protein directly to the fusion of two bilayers.
Structural basis for paramyxovirus-mediated membrane fusion.,Baker KA, Dutch RE, Lamb RA, Jardetzky TS Mol Cell. 1999 Mar;3(3):309-19. PMID:10198633[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Baker KA, Dutch RE, Lamb RA, Jardetzky TS. Structural basis for paramyxovirus-mediated membrane fusion. Mol Cell. 1999 Mar;3(3):309-19. PMID:10198633
