ID   VP1_BFPYV               Reviewed;         343 AA.
AC   P13891; Q9WG02;
DT   01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1990, sequence version 1.
DT   02-DEC-2020, entry version 90.
DE   RecName: Full=Major capsid protein VP1;
DE   AltName: Full=Major structural protein VP1;
OS   Budgerigar fledgling disease virus (BFPyV) (Aves polyomavirus 1).
OC   Viruses; Monodnaviria; Shotokuvirae; Cossaviricota; Papovaviricetes;
OC   Sepolyvirales; Polyomaviridae; Gammapolyomavirus.
OX   NCBI_TaxID=1891747;
OH   NCBI_TaxID=9224; Psittacidae (parrots).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=2838972; DOI=10.1016/0042-6822(88)90660-5;
RA   Rott O., Kroeger M., Mueller H., Hobom G.;
RT   "The genome of budgerigar fledgling disease virus, an avian polyomavirus.";
RL   Virology 165:74-86(1988).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Lafferty S.L., Fudge A.M., Schmidt R.E., Wilson V.G., Phalen D.N.;
RT   "Avian polyomavirus infection and disease in a green aracaris (Pteroglossus
RT   viridis).";
RL   Submitted (JAN-1999) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   REVIEW.
RX   PubMed=19157478; DOI=10.1016/j.virol.2008.12.021;
RA   Neu U., Stehle T., Atwood W.J.;
RT   "The Polyomaviridae: Contributions of virus structure to our understanding
RT   of virus receptors and infectious entry.";
RL   Virology 384:389-399(2009).
RN   [4]
RP   STRUCTURE BY ELECTRON MICROSCOPY.
RX   PubMed=21239031; DOI=10.1016/j.virol.2010.12.005;
RA   Shen P.S., Enderlein D., Nelson C.D., Carter W.S., Kawano M., Xing L.,
RA   Swenson R.D., Olson N.H., Baker T.S., Cheng R.H., Atwood W.J., Johne R.,
RA   Belnap D.M.;
RT   "The structure of avian polyomavirus reveals variably sized capsids, non-
RT   conserved inter-capsomere interactions, and a possible location of the
RT   minor capsid protein VP4.";
RL   Virology 411:142-152(2011).
CC   -!- FUNCTION: Forms an icosahedral capsid with a T=7 symmetry and a 46-48
CC       nm diameter. The capsid is composed of 72 pentamers linked to each
CC       other by disulfide bonds and associated with VP2 or VP3 proteins.
CC       Interacts with sialic acids on the cell surface to provide virion
CC       attachment to target cell. Once attached, the virion is internalized by
CC       endocytosis and traffics to the endoplasmic reticulum. Inside the
CC       endoplasmic reticulum, the protein folding machinery isomerizes VP1
CC       interpentamer disulfide bonds, thereby triggering initial uncoating.
CC       Next, the virion uses the endoplasmic reticulum-associated degradation
CC       machinery to probably translocate in the cytosol before reaching the
CC       nucleus. Nuclear entry of the viral DNA involves the selective exposure
CC       and importin recognition of VP2/Vp3 nuclear localization signal. In
CC       late phase of infection, neo-synthesized VP1 encapsulates replicated
CC       genomic DNA in the nucleus, and participates in rearranging nucleosomes
CC       around the viral DNA (By similarity). {ECO:0000250}.
CC   -!- SUBUNIT: Homomultimer; disulfide-linked. The virus capsid is composed
CC       of 72 icosahedral units, each one composed of five disulfide-linked
CC       copies of VP1. Interacts with minor capsid proteins VP2 and VP3 (By
CC       similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Virion. Host nucleus {ECO:0000250}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing, Alternative initiation; Named isoforms=7;
CC       Name=VP1;
CC         IsoId=P13891-1; Sequence=Displayed;
CC       Name=VP2; Synonyms=Minor capsid protein VP2;
CC         IsoId=P13892-1; Sequence=External;
CC       Name=VP3; Synonyms=Minor capsid protein VP3;
CC         IsoId=P13892-2; Sequence=External;
CC       Name=Agno-1a;
CC         IsoId=A6QL29-1; Sequence=External;
CC       Name=Agno-1b;
CC         IsoId=A6QL29-2; Sequence=External;
CC       Name=Agno-2b;
CC         IsoId=P13893-1; Sequence=External;
CC       Name=Agno-2a;
CC         IsoId=P13893-2; Sequence=External;
CC   -!- DOMAIN: The N-terminal region contains a nuclear signal but the
CC       presence of VP2 and VP3 proteins is required for efficient nuclear
CC       transport. {ECO:0000250}.
CC   -!- MISCELLANEOUS: [Isoform VP1]: Produced by alternative splicing of the
CC       late mRNA.
CC   -!- SIMILARITY: Belongs to the polyomaviruses coat protein VP1 family.
CC       {ECO:0000305}.
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DR   EMBL; M20775; AAB59759.1; -; Genomic_DNA.
DR   EMBL; AF118150; AAD30960.1; -; Genomic_DNA.
DR   PIR; C29194; VVVPBD.
DR   PDB; 3IYS; EM; -; A/B/C/D/E/F=1-343.
DR   PDBsum; 3IYS; -.
DR   SMR; P13891; -.
DR   Proteomes; UP000134051; Genome.
DR   Proteomes; UP000180851; Genome.
DR   GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:0039620; C:T=7 icosahedral viral capsid; IEA:UniProtKB-KW.
DR   GO; GO:0005198; F:structural molecule activity; IEA:InterPro.
DR   GO; GO:0075509; P:endocytosis involved in viral entry into host cell; IEA:UniProtKB-KW.
DR   GO; GO:0019062; P:virion attachment to host cell; IEA:UniProtKB-KW.
DR   Gene3D; 2.60.175.10; -; 1.
DR   InterPro; IPR000662; Capsid_VP1_Polyomavir.
DR   InterPro; IPR011222; dsDNA_vir_gr_I_capsid.
DR   InterPro; IPR036931; Polyomavir_VP1_sf.
DR   Pfam; PF00718; Polyoma_coat; 1.
DR   PIRSF; PIRSF003376; Capsid_VP1_Polyomavir; 1.
DR   SUPFAM; SSF88648; SSF88648; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Alternative initiation; Alternative splicing; Capsid protein;
KW   Disulfide bond; Host nucleus; Host-virus interaction; Late protein;
KW   Reference proteome; T=7 icosahedral capsid protein;
KW   Viral attachment to host cell; Viral penetration into host cytoplasm;
KW   Virion; Virus endocytosis by host; Virus entry into host cell.
FT   CHAIN           1..343
FT                   /note="Major capsid protein VP1"
FT                   /id="PRO_0000115016"
FT   DISULFID        92
FT                   /note="Interchain (with C-92)"
FT                   /evidence="ECO:0000250"
FT   VARIANT         173
FT                   /note="R -> P"
SQ   SEQUENCE   343 AA;  37414 MW;  632AA2A24F2601DC CRC64;
     MSQKGKGSCP RPQQVPRLLV KGGIEVLDVK SGPDSITTIE AYLQPRPGQK NGYSTVITVQ
     AEGYQDAPHS TEVPCYSCAR IPLPTINDDI TCPTLLMWEA VSVKTEVVGV SSILNMHSGA
     FRAFNGYGGG FTICGPRIHF FSVGGEPLDL QACMQNSKTV YPAPLIGPGE GERRETAQVL
     DTGYKARLDK DGLYPIECWC PDPAKNENTR YYGNLTGGPE TPPVLAFTNT TTTILLDENG
     VGPLCKGDGL FLSAADVAGT YVDQRGRQYW RGLPRYFSIQ LRKRNVRNPY PVSGLLNSLF
     NDLMPRMTGQ SMQGSDAQVE EVRVYEGMEG LAPEIDMPPK APR