SCAFB_BPG4
ID SCAFB_BPG4 Reviewed; 120 AA.
AC P03634;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 21-JUL-1986, sequence version 1.
DT 03-AUG-2022, entry version 74.
DE RecName: Full=Internal scaffolding protein B;
DE EC=3.4.-.- {ECO:0000250|UniProtKB:P03633};
DE AltName: Full=Scaffolding protein B;
DE Short=GPB;
GN Name=B;
OS Escherichia phage G4 (Bacteriophage G4).
OC Viruses; Monodnaviria; Sangervirae; Phixviricota; Malgrandaviricetes;
OC Petitvirales; Microviridae; Bullavirinae; Gequatrovirus.
OX NCBI_TaxID=10843;
OH NCBI_TaxID=562; Escherichia coli.
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=714153; DOI=10.1038/276236a0;
RA Godson G.N., Barrell B.G., Staden R., Fiddes J.C.;
RT "Nucleotide sequence of bacteriophage G4 DNA.";
RL Nature 276:236-247(1978).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=160951; DOI=10.1016/0022-2836(79)90249-3;
RA Fiddes J.C., Godson G.N.;
RT "Evolution of the three overlapping gene systems in G4 and phi X174.";
RL J. Mol. Biol. 133:19-43(1979).
CC -!- FUNCTION: Participates in the assembly of the viral procapsid in the
CC cytoplasm. Forms first a 12S pre-assembly complex with protein H, and F
CC and G pentamers, then twelve 12S complexes are joined by the D protein
CC to form the procapsid. Internal scaffold protein B is released from the
CC procapsid upon genome packaging. Autoproteolytic activity cleaves
CC protein B and probably facilitates its removal through the pores of the
CC procapsid. {ECO:0000250|UniProtKB:P03633}.
CC -!- SUBUNIT: Component of the procapsid complex composed of 60 copies of
CC the internally located B, 240 copies of the external scaffolding
CC protein D, 60 copies of each of the viral structural proteins F and G
CC proteins, and 12 copies of H. {ECO:0000250|UniProtKB:P03633}.
CC -!- SUBCELLULAR LOCATION: Host cytoplasm {ECO:0000250|UniProtKB:P03633}.
CC -!- PTM: The proteolytic cleavage of the internal scaffolding protein B
CC releases the scaffold protein in order to continue virion assembly.
CC {ECO:0000250|UniProtKB:P03633}.
CC -!- SIMILARITY: Belongs to the microviridae B protein family.
CC {ECO:0000305}.
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DR EMBL; V00657; CAA24013.1; -; Genomic_DNA.
DR EMBL; M10636; AAA32314.1; -; Genomic_DNA.
DR PIR; A04242; ZBBPG4.
DR SMR; P03634; -.
DR Proteomes; UP000002140; Genome.
DR GO; GO:0030430; C:host cell cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0008233; F:peptidase activity; IEA:UniProtKB-KW.
DR GO; GO:0006508; P:proteolysis; IEA:UniProtKB-KW.
DR GO; GO:0019069; P:viral capsid assembly; IEA:InterPro.
DR Gene3D; 4.10.1260.10; -; 1.
DR InterPro; IPR003513; Phage_B.
DR InterPro; IPR038149; Phage_B_sf.
DR Pfam; PF02304; Phage_B; 1.
PE 3: Inferred from homology;
KW Autocatalytic cleavage; Host cytoplasm; Hydrolase; Protease;
KW Reference proteome; Viral capsid assembly; Viral release from host cell.
FT CHAIN 1..120
FT /note="Internal scaffolding protein B"
FT /id="PRO_0000164868"
FT REGION 1..65
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 1..41
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 51..65
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT SITE 76..77
FT /note="Cleavage; by host"
FT /evidence="ECO:0000250|UniProtKB:P03633"
FT SITE 77..78
FT /note="Cleavage; by autolysis"
FT /evidence="ECO:0000250|UniProtKB:P03633"
FT SITE 93..94
FT /note="Cleavage; by autolysis"
FT /evidence="ECO:0000250|UniProtKB:P03633"
FT SITE 108..109
FT /note="Cleavage; by autolysis"
FT /evidence="ECO:0000250|UniProtKB:P03633"
SQ SEQUENCE 120 AA; 13784 MW; 9050281D96F599FC CRC64;
MEQFTQNQNQ PHTQESVQNT NVSQFRNETV INGSPVSGNP DGTDPSGLRR DPVQQHLEAE
RQERAQIEAG KEICRRRFGG ATCDDESAKI HAQFDPNNRS VQPTEFYRFN DHEINKYGYF
