ID   POL2_CPSMV              Reviewed;        1002 AA.
AC   P31630;
DT   01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1993, sequence version 1.
DT   07-OCT-2020, entry version 93.
DE   RecName: Full=RNA2 polyprotein;
DE   AltName: Full=Genome polyprotein M;
DE   AltName: Full=M RNA polyprotein;
DE   AltName: Full=Middle component RNA polyprotein;
DE   AltName: Full=P2;
DE   Contains:
DE     RecName: Full=VP58;
DE     AltName: Full=P58;
DE   Contains:
DE     RecName: Full=Movement protein;
DE              Short=MP;
DE   Contains:
DE     RecName: Full=Large capsid protein;
DE              Short=LCP;
DE     AltName: Full=Coat protein VP37;
DE     AltName: Full=L subunit;
DE     AltName: Full=Large coat protein;
DE   Contains:
DE     RecName: Full=Small capsid protein precursor;
DE     AltName: Full=S subunit;
DE   Contains:
DE     RecName: Full=Mature small capsid protein;
DE              Short=SCP;
DE     AltName: Full=Coat protein VP23;
DE     AltName: Full=Small capsid protein, N-terminus part;
DE     AltName: Full=Small coat protein, N-terminus part;
DE   Contains:
DE     RecName: Full=Small capsid protein C-terminus part;
DE     AltName: Full=Small coat protein C-terminus part;
OS   Cowpea severe mosaic virus (strain DG) (CPSMV).
OC   Viruses; Riboviria; Orthornavirae; Pisuviricota; Pisoniviricetes;
OC   Picornavirales; Secoviridae; Comovirinae; Comovirus.
OX   NCBI_TaxID=31716;
OH   NCBI_TaxID=132433; Calopogonium mucunoides.
OH   NCBI_TaxID=3823; Canavalia ensiformis (Jack bean) (Dolichos ensiformis).
OH   NCBI_TaxID=185703; Centrosema pubescens.
OH   NCBI_TaxID=3829; Crotalaria juncea (Sunn hemp).
OH   NCBI_TaxID=53866; Desmodium.
OH   NCBI_TaxID=3847; Glycine max (Soybean) (Glycine hispida).
OH   NCBI_TaxID=260885; Macroptilium lathyroides.
OH   NCBI_TaxID=3885; Phaseolus vulgaris (Kidney bean) (French bean).
OH   NCBI_TaxID=3891; Psophocarpus tetragonolobus (Winged bean) (Dolichos tetragonolobus).
OH   NCBI_TaxID=157791; Vigna radiata (Mung bean).
OH   NCBI_TaxID=3917; Vigna unguiculata (Cowpea).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA], PROTEIN SEQUENCE OF 434-449, AND
RP   ALTERNATIVE INITIATION.
RX   PubMed=1546463; DOI=10.1016/0042-6822(92)90471-z;
RA   Chen X., Bruening G.;
RT   "Nucleotide sequence and genetic map of cowpea severe mosaic virus RNA 2
RT   and comparisons with RNA 2 of other comoviruses.";
RL   Virology 187:682-692(1992).
CC   -!- FUNCTION: [VP58]: Responsible for viral RNA2 accumulation. May function
CC       by recruiting the RNA1-encoded polyprotein that contains the
CC       replication protein to RNA2 and enable its replication.
CC       {ECO:0000250|UniProtKB:P23009}.
CC   -!- FUNCTION: [Movement protein]: Transports the viral genome to
CC       neighboring plant cells directly through plasmosdesmata, without any
CC       budding. The movement protein allows efficient cell to cell
CC       propagation, by bypassing the host cell wall barrier. Acts by forming a
CC       tubular structure at the host plasmodesmata, enlarging it enough to
CC       allow free passage of virion capsids. Binds to GTP and to single-
CC       stranded RNA and single-stranded DNA in a non-sequence-specific manner.
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- FUNCTION: [Large capsid protein]: Together with the mature small capsid
CC       protein, forms an icosahedral capsid (T=3) enclosing the viral positive
CC       strand RNA genome, with a diameter of approximately 300 Angstroms. The
CC       capsid is formed from 60 copies each of the large and the small capsid
CC       protein. The large capsid protein interacts with the viral RNA.
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- FUNCTION: [Mature small capsid protein]: Together with the large capsid
CC       protein, forms an icosahedral capsid (T=3) enclosing the viral positive
CC       strand RNA genome, with a diameter of approximately 300 Angstroms. The
CC       capsid is formed from 60 copies each of the large and the small capsid
CC       protein. The mature small capsid protein forms the turrets at the
CC       fivefold axes of the viral particle. {ECO:0000250|UniProtKB:P03599}.
CC   -!- FUNCTION: [Small capsid protein precursor]: The cleavable C-terminus of
CC       small capsid protein seems to be involved in viral assembly and RNA
CC       packaging. After virus assembly, these amino acids are cleaved off
CC       during the normal maturation of the virus. Also seems to act as
CC       suppressor of post-transcriptional gene silencing (PTGS), a mechanism
CC       of plant viral defense that limits the accumulation of viral RNAs.
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- FUNCTION: [Small capsid protein C-terminus part]: Acts as a suppressor
CC       of RNA-mediated gene silencing, also known as post-transcriptional gene
CC       silencing (PTGS), a mechanism of plant viral defense that limits the
CC       accumulation of viral RNAs. {ECO:0000250|UniProtKB:P03599}.
CC   -!- SUBUNIT: [Mature small capsid protein]: Interacts with the large capsid
CC       protein. {ECO:0000250|UniProtKB:P03599}.
CC   -!- SUBUNIT: [Large capsid protein]: Interacts with the small capsid
CC       protein. Homomultimer; assembles as pentons. Interacts with the
CC       movement protein (via C-terminus). {ECO:0000250|UniProtKB:P03599}.
CC   -!- SUBUNIT: [Movement protein]: Interacts (via C-terminus) with the large
CC       capsid protein. {ECO:0000250|UniProtKB:P03599}.
CC   -!- SUBCELLULAR LOCATION: [Movement protein]: Host cell junction, host
CC       plasmodesma {ECO:0000250|UniProtKB:P03599}. Note=Assembles in tubules
CC       that are embedded within modified plasmodesmata.
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- SUBCELLULAR LOCATION: [Large capsid protein]: Virion
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- SUBCELLULAR LOCATION: [Mature small capsid protein]: Virion
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative initiation; Named isoforms=2;
CC       Name=1; Synonyms=RNA2 polyprotein;
CC         IsoId=P31630-1; Sequence=Displayed;
CC       Name=2;
CC         IsoId=P31630-2; Sequence=VSP_059979;
CC   -!- DOMAIN: [Small capsid protein precursor]: The C-terminus is required
CC       for efficient assembly and RNA packaging.
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- DOMAIN: [Large capsid protein]: Contains a beta-sheet structure called
CC       beta-barrel jelly roll. {ECO:0000250|UniProtKB:P03599}.
CC   -!- DOMAIN: [Mature small capsid protein]: Contains a beta-sheet structure
CC       called beta-barrel jelly roll. {ECO:0000250|UniProtKB:P03599}.
CC   -!- DOMAIN: [Movement protein]: The C-terminus is involved in binding to
CC       the large capsid protein, and hence to the virion.
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- PTM: [RNA2 polyprotein]: Specific enzymatic cleavages by picornain 3C-
CC       like protease in vivo yield mature proteins.
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- PTM: [Small capsid protein precursor]: The C-terminal amino acids of
CC       the small capsid protein is specifically cleaved by the RNA1 encoded
CC       picornain 3C-like protease during maturation.
CC       {ECO:0000250|UniProtKB:P03599}.
CC   -!- CAUTION: It is uncertain whether Met-1 or Met-93 is the initiator.
CC       {ECO:0000305}.
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DR   EMBL; M83309; -; NOT_ANNOTATED_CDS; Genomic_RNA.
DR   PIR; A42454; GNWXCS.
DR   SMR; P31630; -.
DR   Proteomes; UP000008566; Genome.
DR   GO; GO:0044219; C:host cell plasmodesma; IEA:UniProtKB-SubCell.
DR   GO; GO:0039617; C:T=3 icosahedral viral capsid; IEA:UniProtKB-KW.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0005198; F:structural molecule activity; IEA:InterPro.
DR   GO; GO:0046740; P:transport of virus in host, cell to cell; IEA:UniProtKB-KW.
DR   Gene3D; 2.60.120.20; -; 2.
DR   InterPro; IPR003181; Como_LCP.
DR   InterPro; IPR003182; RNA2_polyprotein.
DR   InterPro; IPR029053; Viral_coat.
DR   Pfam; PF02247; Como_LCP; 1.
DR   Pfam; PF02248; Como_SCP; 1.
PE   1: Evidence at protein level;
KW   Alternative initiation; Capsid protein; Direct protein sequencing;
KW   DNA-binding; GTP-binding; Host cell junction; Nucleotide-binding;
KW   RNA-binding; Suppressor of RNA silencing; T=3 icosahedral capsid protein;
KW   Transport; Viral movement protein; Virion.
FT   CHAIN           1..1002
FT                   /note="RNA2 polyprotein"
FT                   /id="PRO_0000445842"
FT   CHAIN           1..433
FT                   /note="VP58"
FT                   /id="PRO_0000445843"
FT   CHAIN           93..433
FT                   /note="Movement protein"
FT                   /id="PRO_0000037028"
FT   CHAIN           434..807
FT                   /note="Large capsid protein"
FT                   /id="PRO_0000037029"
FT   CHAIN           808..1002
FT                   /note="Small capsid protein precursor"
FT                   /id="PRO_0000445844"
FT   CHAIN           808..985
FT                   /note="Mature small capsid protein"
FT                   /id="PRO_0000037030"
FT   CHAIN           986..1002
FT                   /note="Small capsid protein C-terminus part"
FT                   /id="PRO_0000445845"
FT   REGION          46..68
FT                   /note="Hydrophobic"
FT                   /evidence="ECO:0000255"
FT   REGION          392..398
FT                   /note="Involved in tubule formation by the movement
FT                   protein"
FT                   /evidence="ECO:0000250|UniProtKB:P03599"
FT   SITE            433..434
FT                   /note="Cleavage; by viral protease"
FT                   /evidence="ECO:0000269|PubMed:1546463"
FT   SITE            806..807
FT                   /note="Cleavage; by viral protease"
FT                   /evidence="ECO:0000250|UniProtKB:P03599"
FT   SITE            985..986
FT                   /note="Cleavage"
FT                   /evidence="ECO:0000250|UniProtKB:P03599"
FT   VAR_SEQ         1..92
FT                   /note="Missing (in isoform 2)"
FT                   /id="VSP_059979"
SQ   SEQUENCE   1002 AA;  112109 MW;  9C27751AD5BD7D39 CRC64;
     MSTFRYKCKQ LDQEIQWWFS GTGNRAFWKF EKKLAELHEW YWSLALDPFP YSGFFYKCFY
     ELFQLWVKLG LIVQVSYLIL LLDFFVYTIP KKMASQIETT VEKVKQSGIP ADILRKRAVD
     YWKKNNSHNS QMQDVLPNVD EIYEGMRANI AKYLGRSSTV TSIAKLGKCK VYRKKNIPLA
     NLPSLQTSCV PITLTEESVG NSDYTTEETN SEVKSLHVGA IEIVMNSFAS SDCNILGGFL
     LIDTCHTDIN NAIRSIFVAP MRGGRPIRMI SFPDTLVQIE PNMNKRFQLL CTTSNGDFMQ
     GRDLAMMHVN VLAHAVTHTS TYTPTPYYEK ILSREKGFIV EYLNRMTYAV HNQNHPTEKD
     LLESDFQFDF EGQPVLKRIS STKAIFSKGS SFRYMISGKK EHKIDKPRLE EDGSKSYIDG
     LQDTFDTTHA TLQSGADLFK RNLDDVSTIS DTMLGAMIGQ TKVVIPKTLV AGTVLKSGPL
     SDVMQQGSFR STIALQRTHI ITGKIHVVAM LETAVNTGLG LAICFNSGIR GKASADIYAT
     CSQDAMIWNP SCTKVMQYAF NPNPCSDGWS LAFLERTGYH CVVTCVTGWT GTPLQDTFMT
     INWHISREAC VPKIYTIFDP EPDMMLNRWM GRAIFPQQST QVVRRMPLSI GGGAGAKNSI
     LMNLPNAILS MWRYFKADLE FELIKMSSPY INATIAFFVA FGDLSDDTVN FEAFPHKLIV
     FSDKQDRTTI SFSKDEFLMA WSTQVRPDTK LSEDGCPYLY AITHNGVSSS VEGDFILGIK
     MVGLKAVENI GVNPGIIGSR LLGAVAQSGQ TQQVWNKIWR IGTPPQATDG LFSFSIDLLG
     VELVTDGQEG AVSVLSSSPV ANLLRTAAWK CGTLHVKVVM TGRVTTTRAN WASHTQMSLV
     NSDNAQHYEA QKWSVSTPHA WEKEFSIDIC GPNRGFEMWR SSWSNQTTWI LEFTVAGASQ
     SAIFEIFYRL DNSWKSAGNV LMPPLLVGNP RLDIKGRAAA AA