DNA polymerase IV

UniProtKB accession:  Q47155

Grouped By:  Matching UniProtKB accession

UniProtKB description:  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).