UniProt functional annotation for Q47155



	UniProt functional annotation for Q47155

UniProt code: Q47155.

Organism: Escherichia coli (strain K12).

Taxonomy: Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.

Function: Poorly processive, error-prone DNA polymerase involved in translesion repair and untargeted mutagenesis (PubMed:10488344, PubMed:10801133). Copies undamaged DNA at stalled replication forks, which arise in vivo from mismatched or misaligned primer ends. These misaligned primers can be extended by Pol IV. Exhibits no 3'-5' exonuclease (proofreading) activity (PubMed:10488344). Overexpression of Pol IV results in increased frameshift mutagenesis. It is required for stationary-phase adaptive mutation, which provides the bacterium with flexibility in dealing with environmental stress, enhancing long- term survival and evolutionary fitness. Not seen to be involved in translesion snythesis even when stimulated by the beta slding-clamp and clamp-loading complex, which do however increase non-targeted DNA polymerase efficiency 3,000-fold, may be due to targeting to stalled replication forks on nondamaged DNA (PubMed:10801133, PubMed:16168375). Involved in translesional synthesis, in conjunction with the beta clamp from PolIII (PubMed:14592985, PubMed:14729336). {ECO:0000269|PubMed:10488344, ECO:0000269|PubMed:10801133, ECO:0000269|PubMed:11080171, ECO:0000269|PubMed:11463382, ECO:0000269|PubMed:11751576, ECO:0000269|PubMed:12060704, ECO:0000269|PubMed:14592985, ECO:0000269|PubMed:16168375, ECO:0000269|PubMed:9391106, ECO:0000305|PubMed:14729336}.

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;

Cofactor: Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250}; Note=Binds 2 magnesium ions per subunit. {ECO:0000250};

Subunit: Monomer. Interacts with beta sliding clamp, which confers increased processivity (PubMed:14592985, PubMed:14729336,PubMed:16168375). {ECO:0000269|PubMed:14592985, ECO:0000269|PubMed:14729336, ECO:0000269|PubMed:16168375, ECO:0000305}.

Subcellular location: Cytoplasm {ECO:0000305}.

Induction: By SOS response. A member of the dinB-yafNOP operon (PubMed:12813093). Induced by hydroxyurea (PubMed:20005847). {ECO:0000269|PubMed:12813093, ECO:0000269|PubMed:20005847}.

Domain: The catalytic core consists of fingers, palm and thumb subdomains, but the fingers and thumb subdomains are much smaller than in high-fidelity polymerases; residues from five sequence motifs of the Y-family cluster around an active site cleft that can accommodate DNA and nucleotide substrates with relaxed geometric constraints, with consequently higher rates of misincorporation and low processivity. It lacks the O helices present in high-fidelity DNA polymerases in the fingers domain (By similarity). {ECO:0000250}.

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

Annotations taken from UniProtKB at the EBI.


Organism:		Escherichia coli (strain K12).
Taxonomy:		Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.



Function:		Poorly processive, error-prone DNA polymerase involved in translesion repair and untargeted mutagenesis (PubMed:10488344, PubMed:10801133). Copies undamaged DNA at stalled replication forks, which arise in vivo from mismatched or misaligned primer ends. These misaligned primers can be extended by Pol IV. Exhibits no 3'-5' exonuclease (proofreading) activity (PubMed:10488344). Overexpression of Pol IV results in increased frameshift mutagenesis. It is required for stationary-phase adaptive mutation, which provides the bacterium with flexibility in dealing with environmental stress, enhancing long- term survival and evolutionary fitness. Not seen to be involved in translesion snythesis even when stimulated by the beta slding-clamp and clamp-loading complex, which do however increase non-targeted DNA polymerase efficiency 3,000-fold, may be due to targeting to stalled replication forks on nondamaged DNA (PubMed:10801133, PubMed:16168375). Involved in translesional synthesis, in conjunction with the beta clamp from PolIII (PubMed:14592985, PubMed:14729336). {ECO:0000269\|PubMed:10488344, ECO:0000269\|PubMed:10801133, ECO:0000269\|PubMed:11080171, ECO:0000269\|PubMed:11463382, ECO:0000269\|PubMed:11751576, ECO:0000269\|PubMed:12060704, ECO:0000269\|PubMed:14592985, ECO:0000269\|PubMed:16168375, ECO:0000269\|PubMed:9391106, ECO:0000305\|PubMed:14729336}.


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;
Cofactor:		Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250}; Note=Binds 2 magnesium ions per subunit. {ECO:0000250};
Subunit:		Monomer. Interacts with beta sliding clamp, which confers increased processivity (PubMed:14592985, PubMed:14729336,PubMed:16168375). {ECO:0000269\|PubMed:14592985, ECO:0000269\|PubMed:14729336, ECO:0000269\|PubMed:16168375, ECO:0000305}.
Subcellular location:		Cytoplasm {ECO:0000305}.
Induction:		By SOS response. A member of the dinB-yafNOP operon (PubMed:12813093). Induced by hydroxyurea (PubMed:20005847). {ECO:0000269\|PubMed:12813093, ECO:0000269\|PubMed:20005847}.
Domain:		The catalytic core consists of fingers, palm and thumb subdomains, but the fingers and thumb subdomains are much smaller than in high-fidelity polymerases; residues from five sequence motifs of the Y-family cluster around an active site cleft that can accommodate DNA and nucleotide substrates with relaxed geometric constraints, with consequently higher rates of misincorporation and low processivity. It lacks the O helices present in high-fidelity DNA polymerases in the fingers domain (By similarity). {ECO:0000250}.
Similarity:		Belongs to the DNA polymerase type-Y family. {ECO:0000305}.