Structural highlights
Function
[SPIKE_CVHSA] S1 attaches the virion to the cell membrane by interacting with human ACE2 and CLEC4M/DC-SIGNR, initiating the infection. Binding to the receptor and internalization of the virus into the endosomes of the host cell probably induces conformational changes in the S glycoprotein. Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membranes fusion within endosomes. S2 is a class I viral fusion protein. Under the current model, the protein has at least three 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.
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
The spike (S) protein of the severe acute respiratory syndrome coronavirus (SARS-CoV) is responsible for host cell attachment and fusion of the viral and host cell membranes. Within S the receptor binding domain (RBD) mediates the interaction with angiotensin-converting enzyme 2 (ACE2), the SARS-CoV host cell receptor. Both S and the RBD are highly immunogenic and both have been found to elicit neutralizing antibodies. Reported here is the X-ray crystal structure of the RBD in complex with the Fab of a neutralizing mouse monoclonal antibody, F26G19, elicited by immunization with chemically inactivated SARS-CoV. The RBD-F26G19 Fab complex represents the first example of the structural characterization of an antibody elicited by an immune response to SARS-CoV or any fragment of it. The structure reveals that the RBD surface recognized by F26G19 overlaps significantly with the surface recognized by ACE2 and, as such, suggests that F26G19 likely neutralizes SARS-CoV by blocking the virus-host cell interaction.
Structural insights into immune recognition of the severe acute respiratory syndrome coronavirus S protein receptor binding domain.,Pak JE, Sharon C, Satkunarajah M, Auperin TC, Cameron CM, Kelvin DJ, Seetharaman J, Cochrane A, Plummer FA, Berry JD, Rini JM J Mol Biol. 2009 May 15;388(4):815-23. Epub 2009 Mar 24. PMID:19324051[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Pak JE, Sharon C, Satkunarajah M, Auperin TC, Cameron CM, Kelvin DJ, Seetharaman J, Cochrane A, Plummer FA, Berry JD, Rini JM. Structural insights into immune recognition of the severe acute respiratory syndrome coronavirus S protein receptor binding domain. J Mol Biol. 2009 May 15;388(4):815-23. Epub 2009 Mar 24. PMID:19324051 doi:10.1016/j.jmb.2009.03.042
