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Viroporin VP2

VP2 of SV40 virus

SV40 VP4 viroporin protein of 125 aas and 1 TMS (Raghava et al. 2011).  It forms Ca2+-selective toroidal pores to disrupt membranes for viral particle release (Raghava et al. 2013; Scott and Griffin 2015).

VP4 of Simian Virus 40 (SV40)

VP2 protein of 240 aas and 1 TMS.

VP2 of Pan troglodytes verus polyomavirus 1a

VP3 protein of 190 aas and 1 TMS

VP3 of Chimpanzee polyomavirus

The structure of the polyomavirus internal protein including a synthetic fragment of 18 aas in which the C-terminal sequence is derived from Vp2 of 319 aas and a 283 aa fragment of the major capsid protein Vp1, which has a full length of 384 aas, is known (1CN3), providing insight into their involvement in viral entry (Chen et al. 1998). The fragments of Vp1 and Vp2, present in this complex, are derived by proteolysis from two large full length proteins, Vp1 and Vp2 as noted above. These full length proteins are included here under TC# 1.A.83.1.5. There are multiple structures reported in PDB of the Vp1 protein: 1CN3, 1SID, 1SIE, 1VPN, 1VPS, 5CPZ, 5CQ0.

Vp2 of polyomavirus

Minor capsid protein VP2/VP3 complex.  Isoforms VP2 and VP3 are structural proteins that reside within the core of the capsid surrounded by 72 VP1 pentamers. They participate in host cell receptor binding together with VP1, the major capsid protein. Following virus endocytosis and trafficking to the endoplasmic reticulum, VP2 and VP3 form oligomers and integrate into the endoplasmic reticulum membrane. Heterooligomer VP2-VP3 may create a viroporin for transporting the viral genome across the ER membrane to the cytoplasm. Nuclear entry of the viral DNA involves the selective exposure and importin recognition of a VP2 or Vp3 nuclear localization signal (shared C-terminus). hey play a role in virion assembly within the nucleus, in particular through a DNA-binding domain located in the C-terminal region. N-terminal myristoylation suggests a scaffold function for virion assembly.

VP2/VP3 of Budgerigar fledgling disease virus (BFPyV) (Aves polyomavirus 1)
VP2, 341 aas with 1 - 2 TMSs, P13892
VP3, 235 aas with 2 - 3 TMSs, D2KCA6