ID   PCPP_BPT4               Reviewed;         212 AA.
AC   P06807; Q38427; Q9T0U1;
DT   01-JAN-1988, integrated into UniProtKB/Swiss-Prot.
DT   19-DEC-2001, sequence version 2.
DT   03-AUG-2022, entry version 94.
DE   RecName: Full=Prohead core protein protease;
DE            EC=3.4.-.-;
DE   AltName: Full=Protein Gp21;
DE   Flags: Precursor;
GN   Name=21;
OS   Enterobacteria phage T4 (Bacteriophage T4).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Caudovirales; Myoviridae; Tevenvirinae; Tequatrovirus.
OX   NCBI_TaxID=10665;
OH   NCBI_TaxID=562; Escherichia coli.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=3552886; DOI=10.1016/0378-1119(86)90285-4;
RA   Keller B., Bickle T.A.;
RT   "The nucleotide sequence of gene 21 of bacteriophage T4 coding for the
RT   prohead protease.";
RL   Gene 49:245-251(1986).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=12626685; DOI=10.1128/mmbr.67.1.86-156.2003;
RA   Miller E.S., Kutter E., Mosig G., Arisaka F., Kunisawa T., Ruger W.;
RT   "Bacteriophage T4 genome.";
RL   Microbiol. Mol. Biol. Rev. 67:86-156(2003).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-15.
RX   PubMed=6512858; DOI=10.1016/0022-2836(84)90073-1;
RA   Keller B., Sengstag C., Kellenberger E., Bickle T.A.;
RT   "Gene 68, a new bacteriophage T4 gene which codes for the 17K prohead core
RT   protein is involved in head size determination.";
RL   J. Mol. Biol. 179:415-430(1984).
CC   -!- FUNCTION: The pathway of bacteriophage T4 head assembly begins with the
CC       formation of a prohead bound to the bacterial cell membrane which is
CC       later converted to the mature, DNA-containing head. During maturation,
CC       all but one of the prohead proteins are proteolytically processed by a
CC       phage-coded protease which is formed by autocatalytic cleavage of the
CC       product of gene 21 (gp21). Protease gp21 has been tentatively located
CC       in the center of the prohead core.
CC   -!- SUBCELLULAR LOCATION: Virion {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the peptidase U9 family. {ECO:0000305}.
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DR   EMBL; M15359; AAA32501.1; -; Genomic_DNA.
DR   EMBL; AF158101; AAD42426.1; -; Genomic_DNA.
DR   EMBL; J02512; AAA32522.1; -; Genomic_DNA.
DR   EMBL; X01414; CAA25657.1; -; Genomic_DNA.
DR   PIR; JF0025; GPBPT4.
DR   RefSeq; NP_049785.1; NC_000866.4.
DR   PDB; 5JBL; X-ray; 1.94 A; A/B/C/D/E=1-212.
DR   PDBsum; 5JBL; -.
DR   SMR; P06807; -.
DR   MEROPS; S77.001; -.
DR   GeneID; 1258771; -.
DR   KEGG; vg:1258771; -.
DR   Proteomes; UP000009087; Genome.
DR   GO; GO:0008233; F:peptidase activity; IEA:UniProtKB-KW.
DR   GO; GO:0006508; P:proteolysis; IEA:UniProtKB-KW.
DR   GO; GO:0046797; P:viral procapsid maturation; IEA:UniProtKB-KW.
DR   InterPro; IPR005082; Peptidase_U9_T4_prohead.
DR   Pfam; PF03420; Peptidase_S77; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Autocatalytic cleavage; Hydrolase; Protease;
KW   Reference proteome; Viral capsid assembly; Viral capsid maturation;
KW   Viral release from host cell; Virion.
FT   CHAIN           1..206
FT                   /note="Prohead core protein protease"
FT                   /id="PRO_0000079182"
FT   PROPEP          207..212
FT                   /id="PRO_0000224184"
FT   SITE            206..207
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255"
FT   CONFLICT        13
FT                   /note="Q -> K (in Ref. 3)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        152
FT                   /note="E -> K (in Ref. 1; AAA32501)"
FT                   /evidence="ECO:0000305"
FT   STRAND          5..10
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          15..19
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          38..49
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          54..56
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   HELIX           59..72
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   TURN            73..77
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          80..84
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          87..90
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   HELIX           93..95
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          96..106
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          109..116
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          119..122
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   HELIX           123..133
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          138..145
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          147..149
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          151..153
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          155..157
FT                   /evidence="ECO:0007829|PDB:5JBL"
FT   STRAND          162..170
FT                   /evidence="ECO:0007829|PDB:5JBL"
SQ   SEQUENCE   212 AA;  23251 MW;  8CB2A799B10CF44F CRC64;
     MNEPQLLIET WGQPGEIIDG VPMLESHDGK DLGLKPGLYI EGIFMQAEVV NRNKRLYPKR
     ILEKAVKDYI NEQVLTKQAL GELNHPPRAN VDPMQAAIII EDMWWKGNDV YGRARVIEGD
     HGPGDKLAAN IRAGWIPGVS SRGLGSLTDT NEGYRIVNEG FKLTVGVDAV WGPSAPDAWV
     TPKEITESQT AEADTSADDA YMALAEAMKK AL