Expanded Substrate Scope of DNA Polymerase θ and DNA Polymerase β: Lyase Activity on 5'-Overhangs and Clustered Lesions.

ABSTRACT: DNA polymerase θ (Pol θ) is a multifunctional enzyme with double-strand break (DSB) repair, translesion synthesis, and lyase activities. Pol θ lyase activity on ternary substrates containing a 5'-dRP that are produced during base excision repair of abasic sites (AP) is weak compared to that of DNA polymerase β (Pol β), a polymerase integrally involved in base excision repair. This led us to explore whether Pol θ utilizes its lyase activity to remove 5'-dRP and incise abasic sites from alternative substrates that might be produced during DNA damage and repair. We found that Pol θ exhibited lyase activity on abasic lesions near DSB termini and on clustered lesions. To calibrate the Pol θ activity, Pol β reactivity was examined with the same substrates. Pol β excised 5'-dRP from within a 5'-o

SUBMITTER: Laverty DJ 

PROVIDER: S-EPMC6200648 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature