UniProt functional annotation for P03680



	UniProt functional annotation for P03680

UniProt code: P03680.

Organism: Bacillus phage phi29 (Bacteriophage phi-29).

Taxonomy: Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes; Caudovirales; Podoviridae; Picovirinae; Salasvirus.

Function: Polymerase responsible for protein-primed viral DNA replication by strand displacement with high processivity and fidelity (PubMed:3863101) (PubMed:2498321). To start replication, the DNA polymerase forms a heterodimer with a free primer terminal protein (TP), recognizes the replication origins at both 5' ends of the linear chromosome, and initiates replication using as primer the OH-group of Ser-232 of the TP (PubMed:22210885). This polymerase possesses three enzymatic activities: DNA synthesis (polymerase), primer terminal protein (TP) deoxynucleotidylation, which is the formation of a covalent linkage (phosphoester) between the hydroxyl group of a specific serine residue in TP and 5'-dAMP, a reaction directed by the second T at the 3' end, and 3' to 5' exonuclease activity (PubMed:2790959). Exonuclease activity has a proofreading purpose (PubMed:2790959). DNA polymerase edits the polymerization errors using an intramolecular pathway as the primer terminus travels from one active site to the other without dissociation from the DNA (PubMed:10493855). DNA polymerization catalyzed by the DNA polymerase is a highly accurate process, but the protein-primed initiation is a quite inaccurate reaction (PubMed:8428945). Since the polymerase initiates the replication on the second thymine, the TP-dAMP initiation product translocates backwards to recover the template information of the first nucleotide (sliding back-mechanism) (PubMed:19011105). {ECO:0000269|PubMed:10493855, ECO:0000269|PubMed:1730646, ECO:0000269|PubMed:19011105, ECO:0000269|PubMed:22210885, ECO:0000269|PubMed:2498321, ECO:0000269|PubMed:2790959, ECO:0000269|PubMed:3863101, ECO:0000269|PubMed:8428945, ECO:0000269|PubMed:9171364}.

Catalytic activity: Reaction=a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1); Xref=Rhea:RHEA:22508, Rhea:RHEA-COMP:11130, Rhea:RHEA-COMP:11131, ChEBI:CHEBI:33019, ChEBI:CHEBI:61560, ChEBI:CHEBI:83828; EC=2.7.7.7; Evidence={ECO:0000269|PubMed:3863101};

Cofactor: Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000269|PubMed:1310035, ECO:0000269|PubMed:15608377, ECO:0000269|PubMed:17611604, ECO:0000269|PubMed:9784372};

Subunit: Interacts with the primer terminal protein; this interaction allows the initiation of TP-primed DNA replication at both viral DNA ends. Interacts with DNA. {ECO:0000269|PubMed:11884636, ECO:0000269|PubMed:22210885, ECO:0000269|PubMed:9931249}.

Domain: The N-terminus contains the 3'-5' exonuclease activity and strand displacement ability (PubMed:8621470). The conserved motif YxGG/A located between the 3'-5' exonuclease and polymerization domains is important for DNA-binding, coordination between DNA synthesis and degradation and for the formation of a stable complex between TP and the DNA polymerase (PubMed:8670845, PubMed:9931249, PubMed:15777661). The C-terminus is involved in the protein-primed initiation, DNA polymerization and pyrophosphorolytic activities (PubMed:8621470, PubMed:1850426). The YCDTD motif is essential for the pyrophosphorolytic activity (PubMed:1850426). The TPR2 region is necessary for the strand displacement coupled to DNA synthesis and probably also for allowing the TP priming domain to move out from the polymerase during transition from initiation to elongation (PubMed:15845765, PubMed:19033368). {ECO:0000269|PubMed:15845765, ECO:0000269|PubMed:1850426, ECO:0000269|PubMed:19033368, ECO:0000269|PubMed:8621470, ECO:0000269|PubMed:9614939, ECO:0000269|PubMed:9931249}.

Miscellaneous: This DNA polymerase requires a protein as a primer. {ECO:0000269|PubMed:16511564}.

Similarity: Belongs to the DNA polymerase type-B family. {ECO:0000305}.

Sequence caution: Sequence=ACE96023.1; Type=Erroneous initiation; Note=Truncated N-terminus.;

Annotations taken from UniProtKB at the EBI.


Organism:		Bacillus phage phi29 (Bacteriophage phi-29).
Taxonomy:		Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes; Caudovirales; Podoviridae; Picovirinae; Salasvirus.



Function:		Polymerase responsible for protein-primed viral DNA replication by strand displacement with high processivity and fidelity (PubMed:3863101) (PubMed:2498321). To start replication, the DNA polymerase forms a heterodimer with a free primer terminal protein (TP), recognizes the replication origins at both 5' ends of the linear chromosome, and initiates replication using as primer the OH-group of Ser-232 of the TP (PubMed:22210885). This polymerase possesses three enzymatic activities: DNA synthesis (polymerase), primer terminal protein (TP) deoxynucleotidylation, which is the formation of a covalent linkage (phosphoester) between the hydroxyl group of a specific serine residue in TP and 5'-dAMP, a reaction directed by the second T at the 3' end, and 3' to 5' exonuclease activity (PubMed:2790959). Exonuclease activity has a proofreading purpose (PubMed:2790959). DNA polymerase edits the polymerization errors using an intramolecular pathway as the primer terminus travels from one active site to the other without dissociation from the DNA (PubMed:10493855). DNA polymerization catalyzed by the DNA polymerase is a highly accurate process, but the protein-primed initiation is a quite inaccurate reaction (PubMed:8428945). Since the polymerase initiates the replication on the second thymine, the TP-dAMP initiation product translocates backwards to recover the template information of the first nucleotide (sliding back-mechanism) (PubMed:19011105). {ECO:0000269\|PubMed:10493855, ECO:0000269\|PubMed:1730646, ECO:0000269\|PubMed:19011105, ECO:0000269\|PubMed:22210885, ECO:0000269\|PubMed:2498321, ECO:0000269\|PubMed:2790959, ECO:0000269\|PubMed:3863101, ECO:0000269\|PubMed:8428945, ECO:0000269\|PubMed:9171364}.


Catalytic activity:		Reaction=a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1); Xref=Rhea:RHEA:22508, Rhea:RHEA-COMP:11130, Rhea:RHEA-COMP:11131, ChEBI:CHEBI:33019, ChEBI:CHEBI:61560, ChEBI:CHEBI:83828; EC=2.7.7.7; Evidence={ECO:0000269\|PubMed:3863101};
Cofactor:		Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000269\|PubMed:1310035, ECO:0000269\|PubMed:15608377, ECO:0000269\|PubMed:17611604, ECO:0000269\|PubMed:9784372};
Subunit:		Interacts with the primer terminal protein; this interaction allows the initiation of TP-primed DNA replication at both viral DNA ends. Interacts with DNA. {ECO:0000269\|PubMed:11884636, ECO:0000269\|PubMed:22210885, ECO:0000269\|PubMed:9931249}.
Domain:		The N-terminus contains the 3'-5' exonuclease activity and strand displacement ability (PubMed:8621470). The conserved motif YxGG/A located between the 3'-5' exonuclease and polymerization domains is important for DNA-binding, coordination between DNA synthesis and degradation and for the formation of a stable complex between TP and the DNA polymerase (PubMed:8670845, PubMed:9931249, PubMed:15777661). The C-terminus is involved in the protein-primed initiation, DNA polymerization and pyrophosphorolytic activities (PubMed:8621470, PubMed:1850426). The YCDTD motif is essential for the pyrophosphorolytic activity (PubMed:1850426). The TPR2 region is necessary for the strand displacement coupled to DNA synthesis and probably also for allowing the TP priming domain to move out from the polymerase during transition from initiation to elongation (PubMed:15845765, PubMed:19033368). {ECO:0000269\|PubMed:15845765, ECO:0000269\|PubMed:1850426, ECO:0000269\|PubMed:19033368, ECO:0000269\|PubMed:8621470, ECO:0000269\|PubMed:9614939, ECO:0000269\|PubMed:9931249}.
Miscellaneous:		This DNA polymerase requires a protein as a primer. {ECO:0000269\|PubMed:16511564}.
Similarity:		Belongs to the DNA polymerase type-B family. {ECO:0000305}.
Sequence caution:		Sequence=ACE96023.1; Type=Erroneous initiation; Note=Truncated N-terminus.;