3s7v
From Proteopedia
Unassembled KI Polyomavirus VP1 Pentamer
Structural highlights
Function[VP1_POVKI] Forms an icosahedral capsid with a T=7 symmetry and a 40 nm diameter. The capsid is composed of 72 pentamers linked to each other by disulfide bonds and associated with VP2 or VP3 proteins. Interacts with sialic acids on the cell surface to provide virion attachment to target cell. Once attached, the virion is internalized by endocytosis and traffics to the endoplasmic reticulum. Inside the endoplasmic reticulum, the protein folding machinery isomerizes VP1 interpentamer disulfide bonds, thereby triggering initial uncoating. Next, the virion uses the endoplasmic reticulum-associated degradation machinery to probably translocate in the cytosol before reaching the nucleus. Nuclear entry of the viral DNA involves the selective exposure and importin recognition of VP2/Vp3 nuclear localization signal. In late phase of infection, neo-synthesized VP1 encapsulates replicated genomic DNA in the nucleus, and participates in rearranging nucleosomes around the viral DNA (By similarity). Publication Abstract from PubMedThe Karolinska Institutet and Washington University polyomaviruses (KIPyV and WUPyV, respectively) are recently discovered human viruses that infect the respiratory tract. Although they have not yet been linked to disease, they are prevalent in populations worldwide, with initial infection occurring in early childhood. Polyomavirus capsids consist of 72 pentamers of the major capsid protein viral protein 1 (VP1), which determines antigenicity and receptor specificity. The WUPyV and KIPyV VP1 proteins are distant in evolution from VP1 proteins of known structure such as simian virus 40 or murine polyomavirus. We present here the crystal structures of unassembled recombinant WUPyV and KIPyV VP1 pentamers at resolutions of 2.9 and 2.55 A, respectively. The WUPyV and KIPyV VP1 core structures fold into the same beta-sandwich that is a hallmark of all polyomavirus VP1 proteins crystallized to date. However, differences in sequence translate into profoundly different surface loop structures in KIPyV and WUPyV VP1 proteins. Such loop structures have not been observed for other polyomaviruses, and they provide initial clues about the possible interactions of these viruses with cell surface receptors. Structures of the major capsid proteins of the human karolinska institutet and washington university polyomaviruses.,Neu U, Wang J, Macejak D, Garcea RL, Stehle T J Virol. 2011 Jul;85(14):7384-92. Epub 2011 May 4. PMID:21543504[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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