ID   TERM_BPB03              Reviewed;         266 AA.
AC   Q37883;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   29-SEP-2021, entry version 72.
DE   RecName: Full=DNA terminal protein;
DE   AltName: Full=Gene product 3;
DE            Short=gp3;
DE   AltName: Full=Protein p3;
GN   Name=3;
OS   Bacillus phage B103 (Bacteriophage B103).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Caudovirales; Salasmaviridae; Picovirinae; Beecentumtrevirus.
OX   NCBI_TaxID=10778;
OH   NCBI_TaxID=1423; Bacillus subtilis.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=9358052; DOI=10.1016/s0378-1119(97)00363-6;
RA   Pecenkova T., Benes V., Paces J., Vlcek C., Paces V.;
RT   "Bacteriophage B103: complete DNA sequence of its genome and relationship
RT   to other Bacillus phages.";
RL   Gene 199:157-163(1997).
CC   -!- FUNCTION: Acts as a primer for DNA elongation during viral genomic
CC       replication. Acts as the small terminase protein during packaging.
CC       Recruits the phage DNA polymerase to the bacterial nucleoid. Primer
CC       terminal protein (TP) is covalently linked to the 5'-ends of both
CC       strands of the genome through a phosphodiester bond between the beta-
CC       hydroxyl group of a serine residue and the 5'-phosphate of the terminal
CC       deoxyadenylate (dAMP). To start replication, the DNA polymerase forms a
CC       heterodimer with a free TP that recognizes the replication origins at
CC       both 5' ends of the linear chromosome, and initiates replication using
CC       as primer the OH-group of Ser-232 of the TP. Since the polymerase
CC       initiates the replication on the second thymine, the TP-dAMP initiation
CC       product slides backwards to recover the template information of the
CC       first nucleotide. {ECO:0000250|UniProtKB:P03681}.
CC   -!- FUNCTION: Hydrolyzes host peptidoglycans during virus entry.
CC       {ECO:0000250|UniProtKB:P03681}.
CC   -!- SUBUNIT: Interacts with the viral polymerase; this interaction allows
CC       the initiation of TP-primed DNA replication at both viral DNA ends.
CC       Binds to ssDNA. Interacts with the replication protein p1. Part of a
CC       DNA-gp3-gp16 complex. {ECO:0000250|UniProtKB:P03681}.
CC   -!- SUBCELLULAR LOCATION: Virion {ECO:0000250|UniProtKB:P03681}.
CC       Note=Associates with the host bacterial nucleoid through its N-terminal
CC       region. {ECO:0000250|UniProtKB:P03681}.
CC   -!- SIMILARITY: Belongs to the phi29likevirus DNA terminal protein family.
CC       {ECO:0000305}.
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DR   EMBL; X99260; CAA67650.1; -; Genomic_DNA.
DR   RefSeq; NP_690636.1; NC_004165.1.
DR   SMR; Q37883; -.
DR   GeneID; 955358; -.
DR   KEGG; vg:955358; -.
DR   Proteomes; UP000000971; Genome.
DR   GO; GO:0016787; F:hydrolase activity; IEA:UniProtKB-KW.
DR   GO; GO:0098932; P:disruption by virus of host cell wall peptidoglycan during virus entry; IEA:UniProtKB-KW.
DR   GO; GO:0006269; P:DNA replication, synthesis of RNA primer; IEA:InterPro.
DR   GO; GO:0018142; P:protein-DNA covalent cross-linking; IEA:InterPro.
DR   GO; GO:0039693; P:viral DNA genome replication; IEA:UniProtKB-KW.
DR   Gene3D; 1.20.1270.230; -; 1.
DR   InterPro; IPR008770; DNA_terminal_Gp3.
DR   InterPro; IPR043124; DNA_terminal_Gp3_C.
DR   InterPro; IPR037216; DNA_terminal_Gp3_sf.
DR   Pfam; PF05435; Phi-29_GP3; 1.
DR   PIRSF; PIRSF004179; Phi-29_GP3; 1.
DR   SUPFAM; SSF140919; SSF140919; 1.
PE   3: Inferred from homology;
KW   Covalent protein-DNA linkage;
KW   Degradation of host cell envelope components during virus entry;
KW   Degradation of host peptidoglycans during virus entry; DNA replication;
KW   Early protein; Hydrolase; Phosphoprotein; Viral DNA replication; Virion;
KW   Virus entry into host cell.
FT   CHAIN           1..266
FT                   /note="DNA terminal protein"
FT                   /id="PRO_0000106552"
FT   REGION          1..73
FT                   /note="Disordered"
FT                   /evidence="ECO:0000250|UniProtKB:P03681"
FT   REGION          74..172
FT                   /note="Intermediate; makes extensive contacts with the
FT                   phage DNA polymerase"
FT                   /evidence="ECO:0000250|UniProtKB:P03681"
FT   REGION          173..266
FT                   /note="Priming"
FT                   /evidence="ECO:0000250|UniProtKB:P03681"
FT   REGION          256..258
FT                   /note="Interaction with the viral DNA polymerase"
FT                   /evidence="ECO:0000250|UniProtKB:P03681"
FT   SITE            230
FT                   /note="Positions the 3' end of the template strand at the
FT                   active site of the DNA polymerase"
FT                   /evidence="ECO:0000250|UniProtKB:P03681"
FT   MOD_RES         232
FT                   /note="O-(5'-phospho-DNA)-serine"
FT                   /evidence="ECO:0000250|UniProtKB:P03681"
SQ   SEQUENCE   266 AA;  31297 MW;  5BB5AD081A90FAF3 CRC64;
     MARNSRIRIT NNDKALYAKL VKNTKAKISR TKKKYGIDLS NEIELPPLES FQTRKEFNEW
     KRKQESFTNR ANQNYQFVKN KYGIVASKAK INEIEKNTKE AQRIVDEQRE EIEDKPFISG
     GKQQGTVGQR MQILSPSQVT GVSRPSDFNF DDVRSYARLR TLEEGMAEKA SPDYYDRRMA
     QMHQNFIEIV EKSFNSYWLT DELVERLKKI PPDDFFELYL IFDEISFEYF DSEGEDVEAS
     EAMLNKIHSY LDRYERGDVN LDLKGF