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Publication Abstract from PubMed

Cellular membranes are maintained as closed compartments, broken up only transiently during membrane reorganization or lipid transportation. However, open-ended membranes, likely derived from scissions of the endoplasmic reticulum, persist in vaccinia virus-infected cells during the assembly of the viral envelope. A group of viral membrane assembly proteins (VMAPs) were identified as essential for this process. To understand the mechanism of VMAPs, we determined the 2.2-A crystal structure of the largest member, named A6, which is a soluble protein with two distinct domains. The structure of A6 displays a novel protein fold composed mainly of alpha helices. The larger C-terminal domain forms a unique cage that encloses multiple glycerophospholipids with a lipid bilayer-like configuration. The smaller N-terminal domain does not bind lipid but negatively affects lipid binding by A6. Mutations of key hydrophobic residues lining the lipid-binding cage disrupt lipid binding and abolish viral replication. Our results reveal a protein modality for enclosing the lipid bilayer and provide molecular insight into a viral machinery involved in generating and/or stabilizing open-ended membranes.

Structure of a lipid-bound viral membrane assembly protein reveals a modality for enclosing the lipid bilayer.,Pathak PK, Peng S, Meng X, Han Y, Zhang B, Zhang F, Xiang Y, Deng J Proc Natl Acad Sci U S A. 2018 Jun 18. pii: 1805855115. doi:, 10.1073/pnas.1805855115. PMID:29915071^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.