7pa7

Structural highlights

Function

VP1_POVBK Forms an icosahedral capsid with a T=7 symmetry and a 50 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 gangliosides GT1b and GD1b containing terminal alpha(2-8)-linked sialic acids on the cell surface to provide virion attachment to target cell. This attachment induces virion internalization predominantly through caveolin-mediated 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).^{[1] [2]}

References

1. ↑ Eash S, Querbes W, Atwood WJ. Infection of vero cells by BK virus is dependent on caveolae. J Virol. 2004 Nov;78(21):11583-90. PMID:15479799 doi:http://dx.doi.org/10.1128/JVI.78.21.11583-11590.2004
2. ↑ Low JA, Magnuson B, Tsai B, Imperiale MJ. Identification of gangliosides GD1b and GT1b as receptors for BK virus. J Virol. 2006 Feb;80(3):1361-6. PMID:16415013 doi:http://dx.doi.org/80/3/1361