DNA Polymerase II Supports the Replicative Bypass of -Alkyl-2'-deoxyguanosine Lesions in Cells.

Alkylation represents a main form of DNA damage. The position of guanine is frequently alkylated in DNA. The SOS-induced polymerases have been shown to be capable of bypassing various DNA damage products in . Herein, we explored the influences of four -alkyl-dG lesions (alkyl = ethyl, -butyl, isobutyl, or -butyl) on DNA replication in AB1157 cells and the corresponding strains with polymerases (Pol) II, IV, and V being individually or simultaneously knocked out. We found that -Et-dG is slightly less blocking to DNA replication than the -Bu-dG lesions, which display very similar replication bypass efficiencies. Additionally, Pol II and, to a lesser degree, Pol IV and Pol V are required for the efficient bypass of the -alkyl-dG adducts, and none of these lesions was mutagenic. Together, our results support that the efficient replication across small -alkyl-dG DNA adducts in depends mainly on Pol II.