Polymerase DNA Directed Eta (POLh)

Polymerase (DNA directed), eta, also known as POLH, is a member of the Y family of specialized DNA polymerases. It copies undamaged DNA with a lower fidelity than other DNA-directed polymerases. However, it accurately replicates UV-damaged DNA; when thymine dimers are present, this polymerase inserts the complementary nucleotides in the newly synthesized DNA, thereby bypassing the lesion and suppressing the mutagenic effect of UV-induced DNA damage. This polymerase is thought to be involved in hypermutation during immunoglobulin class switch recombination. Mutations in this gene result in XPV, a variant type of xeroderma pigmentosum.the XP-V gene product is likely to be involved in the process of DNA replication on damaged DNA known as post-replication repair, but not in NER.