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DNA polymerases

Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).


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DNA polymerases (or DNA-directed DNA polymerases) are enzymes that catalyse the addition of deoxyribonucleotides to replicating DNA strands and they play crucial roles in the processes that repair different types of DNA damage.


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DNA polymerase beta Show summary »

DNA polymerase theta Show summary »

Target Id 3230
Nomenclature DNA polymerase theta
Previous and unofficial names POLH | polymerase (DNA directed), theta | polymerase (DNA) theta | POLθ
Genes POLQ (Hs), Polq (Mm), Polq (Rn)
Ensembl ID ENSG00000051341 (Hs), ENSMUSG00000034206 (Mm), ENSRNOG00000002471 (Rn)
UniProtKB AC O75417 (Hs), Q8CGS6 (Mm)
EC number
RP-6685 pIC50 8.2 [1]
ART812 pIC50 8.1 [4]
ART558 pIC50 8.1 [4]
Comment POLθ is the only eukaryotic polymerase with a helicase domain, in addition to its polymerase domain. POLθ-mediated end-joining (TMEJ) is a component of the process of DNA double-strand break (DSB) repair known as microhomology-mediated end-joining (MMEJ), that mammalian cells employ to eliminate cytotoxic DSBs in replicating cells. TMEJ is an alternative DSB repair mechanism that is deployed when canonical DNA repair pathways (such as nonhomologous end-joining/NHEJ and homologous recombination/HR) are compromised by mutations in crucial genes such as BRCA1 and BRCA2. POLθ is being evaluated as an oncology drug target, for potential to exploit synthetic lethality (SL) as a targeted anticancer strategy, in malignancies with defects in NHEJ and/or HR. Inhibition of POLθ's helicase and polymerase domains is being explored [3].


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How to cite this family page

Database page citation:

DNA polymerases. Accessed on 23/06/2024. IUPHAR/BPS Guide to PHARMACOLOGY,

Concise Guide to PHARMACOLOGY citation:

Alexander SPH, Fabbro D, Kelly E, Mathie AA, Peters JA, Veale EL, Armstrong JF, Faccenda E, Harding SD, Davies JA et al. (2023) The Concise Guide to PHARMACOLOGY 2023/24: Enzymes. Br J Pharmacol. 180 Suppl 2:S289-373.