ID   CAPSD_BPMX1             Reviewed;         133 AA.
AC   Q9T0R9;
DT   30-NOV-2010, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   23-FEB-2022, entry version 63.
DE   RecName: Full=Capsid protein;
DE            Short=CP;
DE   AltName: Full=Coat protein;
OS   Escherichia phage Qbeta.
OC   Viruses; Riboviria; Orthornavirae; Lenarviricota; Leviviricetes;
OC   Norzivirales; Fiersviridae; Qubevirus; Qubevirus durum.
OX   NCBI_TaxID=2789016;
OH   NCBI_TaxID=562; Escherichia coli.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=7723040; DOI=10.1006/jmbi.1995.0189;
RA   Beekwilder M.J., Nieuwenhuizen R., van Duin J.;
RT   "Secondary structure model for the last two domains of single-stranded RNA
RT   phage Q beta.";
RL   J. Mol. Biol. 247:903-917(1995).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=8609616; DOI=10.1006/jmbi.1996.0064;
RA   Beekwilder J., Nieuwenhuizen R., Poot R., van Duin J.;
RT   "Secondary structure model for the first three domains of Q beta RNA.
RT   Control of A-protein synthesis.";
RL   J. Mol. Biol. 256:8-19(1996).
RN   [3]
RP   RNA-BINDING.
RX   PubMed=16531233; DOI=10.1016/j.str.2005.12.006;
RA   Horn W.T., Tars K., Grahn E., Helgstrand C., Baron A.J., Lago H.,
RA   Adams C.J., Peabody D.S., Phillips S.E., Stonehouse N.J., Liljas L.,
RA   Stockley P.G.;
RT   "Structural basis of RNA binding discrimination between bacteriophages
RT   Qbeta and MS2.";
RL   Structure 14:487-495(2006).
CC   -!- FUNCTION: Capsid protein self-assembles to form an icosahedral capsid
CC       with a T=3 symmetry, about 26 nm in diameter, and consisting of 89
CC       capsid proteins dimers (178 capsid proteins). Involved in viral genome
CC       encapsidation through the interaction between a capsid protein dimer
CC       and the multiple packaging signals present in the RNA genome. Binding
CC       of the capsid proteins to the viral RNA induces a conformational change
CC       required for efficient T=3 shell formation. The capsid contains also 1
CC       copy of the A2 maturation protein. {ECO:0000250|UniProtKB:P03615}.
CC   -!- FUNCTION: Acts as a translational repressor of viral replicase
CC       synthesis late in infection. This latter function is the result of
CC       capsid protein interaction with an RNA hairpin which contains the
CC       replicase ribosome-binding site. {ECO:0000250|UniProtKB:P03615}.
CC   -!- SUBUNIT: Homodimer. The capsid protein dimer binds to the viral RNA via
CC       an operator hairpin, but also many other RNA sequences in the viral
CC       genome. {ECO:0000250|UniProtKB:P03615}.
CC   -!- SUBCELLULAR LOCATION: Virion {ECO:0000250|UniProtKB:P03615}. Note=The
CC       shell is composed of 89 dimers of the capsid protein and 1 copy of the
CC       maturation protein. {ECO:0000250|UniProtKB:P03615}.
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DR   EMBL; AF059242; AAC14699.1; -; Genomic_RNA.
DR   RefSeq; NP_046751.1; NC_001890.1.
DR   SMR; Q9T0R9; -.
DR   GeneID; 1261502; -.
DR   KEGG; vg:1261502; -.
DR   Proteomes; UP000001832; Genome.
DR   GO; GO:0039617; C:T=3 icosahedral viral capsid; 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:0006417; P:regulation of translation; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.380.10; -; 1.
DR   InterPro; IPR002703; Levivir_coat.
DR   InterPro; IPR015954; Phage_RNA-type_capsid.
DR   Pfam; PF01819; Levi_coat; 1.
DR   SUPFAM; SSF55405; SSF55405; 1.
PE   1: Evidence at protein level;
KW   Capsid protein; Reference proteome; RNA-binding;
KW   T=3 icosahedral capsid protein; Translation regulation; Virion.
FT   INIT_MET        1
FT                   /note="Removed; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P03615"
FT   CHAIN           2..133
FT                   /note="Capsid protein"
FT                   /id="PRO_0000402536"
FT   SITE            90
FT                   /note="RNA-binding"
FT                   /evidence="ECO:0000250|UniProtKB:P03615"
SQ   SEQUENCE   133 AA;  14198 MW;  2559593DAF6F6474 CRC64;
     MAKLQAITLS GIGKNGDVTL NLNPRGVNPT NGVAALSEAG AVPALEKRVT ISVSQPSRNR
     KNYKVQVKIQ NPTSCTASGT CDPSVTRSAY ADVTFSFTQY STDEERALVR TELKALLADP
     MLIDAIDNLN PAY