3mko
Crystal Structure of the Lymphocytic Choriomeningitis Virus Membrane Fusion Glycoprotein GP2 in its Postfusion Conformation
Structural highlights
FunctionGLYC_LYCVW The stable signal peptide (SSP) is cleaved and functions as a signal peptide. In addition, it is apparently retained as the third component of the GP complex. The SSP is required for efficient glycoprotein expression, post-translational maturation cleavage of GP1 and GP2, glycoprotein transport to the cell surface plasma membrane, formation of infectious virus particles, and acid pH-dependent glycoprotein-mediated cell fusion (By similarity). Glycoprotein G1 mediates virus attachment to host receptor alpha-dystroglycan DAG1. This attachment induces virion internalization predominantly through clathrin- and caveolin-independent endocytosis (By similarity). Glycoprotein G2 is a viral fusion protein. Membrane fusion is mediated by conformational changes induced upon acidification in the endosome (Potential). Publication Abstract from PubMedArenaviruses are important agents of zoonotic disease worldwide. The virions expose a tripartite envelope glycoprotein complex at their surface, formed by the glycoprotein subunits GP1, GP2 and the stable signal peptide. This complex is responsible for binding to target cells and for the subsequent fusion of viral and host-cell membranes for entry. During this process, the acidic environment of the endosome triggers a fusogenic conformational change in the transmembrane GP2 subunit of the complex. We report here the crystal structure of the recombinant GP2 ectodomain of the lymphocytic choriomeningitis virus, the arenavirus type species, at 1.8-A resolution. The structure shows the characteristic trimeric coiled coil present in class I viral fusion proteins, with a central stutter that allows a close structural alignment with most of the available structures of class I and III viral fusion proteins. The structure further shows a number of intrachain salt bridges stabilizing the postfusion hairpin conformation, one of which involves an aspartic acid that appears released from a critical interaction with the stable signal peptide upon low pH activation. X-ray structure of the arenavirus glycoprotein GP2 in its postfusion hairpin conformation.,Igonet S, Vaney MC, Vonhrein C, Bricogne G, Stura EA, Hengartner H, Eschli B, Rey FA Proc Natl Acad Sci U S A. 2011 Nov 28. PMID:22123988[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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