8sdf
From Proteopedia
Crystal structure of SARS-CoV-2 receptor binding domain in complex with neutralizing antibody CC25.4
Structural highlights
FunctionSPIKE_SARS2 attaches the virion to the cell membrane by interacting with host receptor, initiating the infection (By similarity). Binding to human ACE2 receptor and internalization of the virus into the endosomes of the host cell induces conformational changes in the Spike glycoprotein (PubMed:32142651, PubMed:32075877, PubMed:32155444). Uses also human TMPRSS2 for priming in human lung cells which is an essential step for viral entry (PubMed:32142651). Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membranes fusion within endosomes.[HAMAP-Rule:MF_04099][1] [2] [3] mediates fusion of the virion and cellular membranes by acting as 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.[HAMAP-Rule:MF_04099] Acts as a viral fusion peptide which is unmasked following S2 cleavage occurring upon virus endocytosis.[HAMAP-Rule:MF_04099] Publication Abstract from PubMedDeveloping broad coronavirus vaccines requires identifying and understanding the molecular basis of broadly neutralizing antibody (bnAb) spike sites. In our previous work, we identified sarbecovirus spike RBD group 1 and 2 bnAbs. We have now shown that many of these bnAbs can still neutralize highly mutated SARS-CoV-2 variants, including the XBB.1.5. Structural studies revealed that group 1 bnAbs use recurrent germline-encoded CDRH3 features to interact with a conserved RBD region that overlaps with class 4 bnAb site. Group 2 bnAbs recognize a less well-characterized "site V" on the RBD and destabilize spike trimer. The site V has remained largely unchanged in SARS-CoV-2 variants and is highly conserved across diverse sarbecoviruses, making it a promising target for broad coronavirus vaccine development. Our findings suggest that targeted vaccine strategies may be needed to induce effective B cell responses to escape resistant subdominant spike RBD bnAb sites. Broadly neutralizing antibodies targeting a conserved silent face of spike RBD resist extreme SARS-CoV-2 antigenic drift.,Song G, Yuan M, Liu H, Capozzola T, Lin RN, Torres JL, He WT, Musharrafieh R, Dueker K, Zhou P, Callaghan S, Mishra N, Yong P, Anzanello F, Avillion G, Vo AL, Li X, Makhdoomi M, Feng Z, Zhu X, Peng L, Nemazee D, Safonova Y, Briney B, Ward AB, Burton DR, Wilson IA, Andrabi R bioRxiv [Preprint]. 2023 Apr 27:2023.04.26.538488. doi: , 10.1101/2023.04.26.538488. PMID:37162858[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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