2xgk
From Proteopedia
Virus like particle of L172W mutant of Minute Virus of Mice - the immunosuppressive strain
Structural highlights
FunctionCAPSD_MUMIM Capsid protein self-assembles to form an icosahedral capsid with a T=1 symmetry, about 22 nm in diameter, and consisting of 60 copies of two size variants of the capsid proteins, VP1 and VP2, which differ by the presence of an N-terminal extension in the minor protein VP1. The capsid encapsulates the genomic ssDNA. Capsid proteins are responsible for the attachment to host cell receptors. This attachment induces virion internalization predominantly through clathrin-dependent endocytosis. Binding to the host receptors also induces capsid rearrangements leading to surface exposure of VP1 N-terminus, specifically its phospholipase A2-like region and putative nuclear localization signal(s). VP1 N-terminus might serve as a lipolytic enzyme to breach the endosomal membrane during entry into host cell and might contribute to virus transport to the nucleus (By similarity). Publication Abstract from PubMedParvovirus Minute Virus of Mice (MVM) packages a single copy of its linear single-stranded DNA genome into pre-formed capsids, in a process that is probably driven by a virus-encoded helicase. Parvoviruses have a roughly cylindrically shaped pore that surrounds each of the twelve fivefold vertices. The pore, which penetrates the virion shell, is created by the juxtaposition of ten anti-parallel beta-strands, two from each of the fivefold related capsid proteins. There is a bottleneck in the channel formed by the symmetry-related sidechains of the leucines at position 172. We report here the X-ray crystal structure of the particles produced by a leucine to tryptophan mutation at position 172 and the analysis of its biochemical properties. The mutant capsid has its fivefold channel blocked and the particles were unable to package DNA, strongly suggesting that the fivefold pore is the packaging portal for genome entry. Structure of a packaging defective mutant of Minute Virus of Mice indicates that the genome is packaged via a pore at a fivefold axis.,Plevka P, Hafenstein S, Li L, D'Abramo A Jr, Cotmore SF, Rossmann MG, Tattersall P J Virol. 2011 Mar 2. PMID:21367911[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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