7kdd | pdb_00007kdd
HCMV postfusion gB in complex with SM5-1 Fab
Structural highlights
FunctionGB_HCMVT Envelope glycoprotein that plays a role in host cell entry, cell to-cell virus transmission, and fusion of infected cells. May be involved in the initial attachment via binding to heparan sulfate together with the gM/gN complex that binds heparin with higher affinity. Interacts with host integrin ITGB1, PDGFRA and EGFR that likely serve as postattachment entry receptors. Participates also in the fusion of viral and cellular membranes leading to virus entry into the host cell. Membrane fusion is mediated by the fusion machinery composed at least of gB and the heterodimer gH/gL (By similarity). Viral ligand for CD209/DC-SIGN. This interaction allows capture of viral particles by dendritic (DCs) cells and subsequent virus transmission to permissive cells. DCs are professional antigen presenting cells, critical for host immunity by inducing specific immune responses against a broad variety of pathogens. They act as sentinels in various tissues where they entrap pathogens and convey them to local lymphoid tissue or lymph node for establishment of immunity. CMV subverts the migration properties of dendritic cells to gain access to target organs or susceptible cells. Publication Abstract from PubMedHuman cytomegalovirus (HCMV) causes congenital disease with long-term morbidity. HCMV glycoprotein B (gB) transitions irreversibly from a metastable prefusion to a stable postfusion conformation to fuse the viral envelope with a host cell membrane during entry. We stabilized prefusion gB on the virion with a fusion inhibitor and a chemical cross-linker, extracted and purified it, and then determined its structure to 3.6-A resolution by electron cryomicroscopy. Our results revealed the structural rearrangements that mediate membrane fusion and details of the interactions among the fusion loops, the membrane-proximal region, transmembrane domain, and bound fusion inhibitor that stabilized gB in the prefusion state. The structure rationalizes known gB antigenic sites. By analogy to successful vaccine antigen engineering approaches for other viral pathogens, the high-resolution prefusion gB structure provides a basis to develop stabilized prefusion gB HCMV vaccine antigens. Prefusion structure of human cytomegalovirus glycoprotein B and structural basis for membrane fusion.,Liu Y, Heim KP, Che Y, Chi X, Qiu X, Han S, Dormitzer PR, Yang X Sci Adv. 2021 Mar 5;7(10). pii: 7/10/eabf3178. doi: 10.1126/sciadv.abf3178. Print, 2021 Mar. PMID:33674318[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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