Polymerase DNA Directed Kappa (POLk)

Members of the Y family of DNA polymerases, such as POLK, permit the continuity of the replication fork by allowing replication through such DNA lesions. Each Y family polymerase has a unique DNA-damage bypass and fidelity profile. POLK is specialized for the extension step of lesion bypass.

The deduced 870-amino acid POLK protein contains an N-terminal conserved nucleotidyl transferase domain, 2 tandem helix-hairpin-helix domains implicated in DNA binding, and a nonconserved C terminus containing 2 zinc clusters. Northern blot analysis revealed ubiquitous expression of a 5.0-kb transcript at low but varying levels in all tissues tested. Highest expression was found in testis, which also had abundant 3.2- and 4.4-kb transcripts.