6p91
Structure of Lassa virus glycoprotein bound to Fab 18.5C
Structural highlights
FunctionGLYC_LASSJ Stable signal peptide (SSP) is cleaved but is apparently retained as the third component of the GP complex. The SSP is required for efficient glycoprotein expression, post-translational cleavage of GP1 and GP2, glycoprotein transport to the cell plasma membrane, formation of infectious virus particles, and acid pH-dependent glycoprotein-mediated cell fusion. The GP complex interacts with host glycosylated LAMP1 to mediate efficient infection.[1] Glycoprotein G1 mediates virus attachment to host receptor alpha-dystroglycan DAG1. This attachment induces virion internalization predominantly through clathrin- and caveolin-independent endocytosis. Glycoprotein G2 is a class I viral fusion protein, that directs fusion of viral and host endosomal membranes, leading to delivery of the nucleocapsid into the cytoplasm. Membrane fusion is mediated by irreversable conformational changes induced upon acidification in the endosome (By similarity). Publication Abstract from PubMedLassa virus (LASV) causes hemorrhagic fever and is endemic in West Africa. Protective antibody responses primarily target the LASV surface glycoprotein (GPC), and GPC-B competition group antibodies often show potent neutralizing activity in humans. However, which features confer potent and broadly neutralizing antibody responses is unclear. Here, we compared three crystal structures of LASV GPC complexed with GPC-B antibodies of varying neutralization potency. Each GPC-B antibody recognized an overlapping epitope involved in binding of two adjacent GPC monomers and preserved the prefusion trimeric conformation. Differences among GPC-antibody interactions highlighted specific residues that enhance neutralization. Using structure-guided amino acid substitutions, we increased the neutralization potency and breadth of these antibodies to include all major LASV lineages. The ability to define antibody residues that allow potent and broad neutralizing activity, together with findings from analyses of inferred germline precursors, is critical to develop potent therapeutics and for vaccine design and assessment. Convergent Structures Illuminate Features for Germline Antibody Binding and Pan-Lassa Virus Neutralization.,Hastie KM, Cross RW, Harkins SS, Zandonatti MA, Koval AP, Heinrich ML, Rowland MM, Robinson JE, Geisbert TW, Garry RF, Branco LM, Saphire EO Cell. 2019 Aug 8;178(4):1004-1015.e14. doi: 10.1016/j.cell.2019.07.020. PMID:31398326[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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