ID   TERS_BPLP7              Reviewed;         162 AA.
AC   P16937;
DT   01-AUG-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1990, sequence version 1.
DT   02-JUN-2021, entry version 57.
DE   RecName: Full=Terminase, small subunit;
DE   AltName: Full=DNA-packaging protein gp3;
GN   Name=3;
OS   Enterobacteria phage LP7 (Bacteriophage LP7).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Caudovirales; Podoviridae; Lederbergvirus.
OX   NCBI_TaxID=10750;
OH   NCBI_TaxID=590; Salmonella.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=2341038; DOI=10.1016/0378-1119(90)90058-y;
RA   Petri J.B., Schmieger H.;
RT   "Isolation of fragments with pac function for phage P22 from phage LP7 DNA
RT   and comparison of packaging gene 3 sequences.";
RL   Gene 88:47-55(1990).
CC   -!- FUNCTION: The terminase small subunit binds to the packaging initiation
CC       site and regulates the ATPase activity of the terminase large subunit.
CC       The terminase lies at a unique vertex of the procapsid and is composed
CC       of two subunits, a small terminase subunit involved in viral DNA
CC       recognition (packaging sequence), and a large terminase subunit
CC       possessing endonucleolytic and ATPase activities. Both terminase
CC       subunits heterooligomerize and are docked on the portal protein to form
CC       the packaging machine. The terminase large subunit exhibits
CC       endonuclease activity and cleaves the viral genome concatemer once the
CC       capsid is full (headful packaging). Once the capsid is packaged with
CC       the DNA, the terminase complex is substituted by neck proteins.
CC       {ECO:0000250|UniProtKB:P04893}.
CC   -!- SUBUNIT: Homononamer; forms a ring-like structure through which genomic
CC       DNA is translocated into the capsid. Heterodimer with the terminase
CC       small subunit gp3; the active complex is probably heterooligomeric.
CC       {ECO:0000250|UniProtKB:P04893}.
CC   -!- SIMILARITY: Belongs to the P22likevirus small terminase family.
CC       {ECO:0000305}.
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DR   EMBL; M32403; AAA88219.1; -; Genomic_DNA.
DR   SMR; P16937; -.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   InterPro; IPR032066; GP3_package.
DR   Pfam; PF16677; GP3_package; 1.
PE   3: Inferred from homology;
KW   DNA-binding; Late protein; Viral genome packaging;
KW   Viral release from host cell.
FT   CHAIN           1..162
FT                   /note="Terminase, small subunit"
FT                   /id="PRO_0000077745"
FT   REGION          132..162
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   162 AA;  18757 MW;  2A2B2D6F2E73C53A CRC64;
     MAAPKGNRFW EARSSHGRNP KFESPEALWA ACCEYFEWVE ANPLWEMKAF SYQGEVTQEP
     IAKMRAMTIT GLTLFLDVTL ETWRQYRVRE DLSEVVTRAE QIIYDQKFSG AADDLLNANI
     IARDLGLKEQ SQFEDVTPDK GDRDKRRSRI KELFNRGTGR DS