biostudies-literatureWang YNational Institute of Environmental Health SciencesNIEHS NIH HHS695-698https://www.ebi.ac.uk/biostudies/studies/S-EPMC7965357biostudies-literatureUnknown34(3)Alkylation represents a main form of DNA damage. The <i>N</i>² 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 <i>Escherichia coli</i>. Herein, we explored the influences of four <i>N</i>²-alkyl-dG lesions (alkyl = ethyl, <i>n</i>-butyl, isobutyl, or <i>sec</i>-butyl) on DNA replication in AB1157 <i>E. coli</i> cells and the corresponding strains with polymerases (Pol) II, IV, and V being individually or simultaneously knocked out. We found that <i>N</i>²-Et-dG is slightly less blocking to DNA replication than the <i>N</i>²-Bu-dG lesions, which display very similar replication bypass efficiencies. Additionally, Pol II and, to a lesser degree,Chemical research in toxicologyDNA Polymerase II Supports the Replicative Bypass of <i>N</i>²-Alkyl-2'-deoxyguanosine Lesions in <i>Escherichia coli</i> Cells.PMC7965357R35 ES031707Wu JWang YfalseDNA Polymerase II Supports the Replicative Bypass of <i>N</i>²-Alkyl-2'-deoxyguanosine Lesions in <i>Escherichia coli</i> Cells.Alkylation represents a main form of DNA damage. The <i>N</i>² 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 <i>Escherichia coli</i>. Herein, we explored the influences of four <i>N</i>²-alkyl-dG lesions (alkyl = ethyl, <i>n</i>-butyl, isobutyl, or <i>sec</i>-butyl) on DNA replication in AB1157 <i>E. coli</i> cells and the corresponding strains with polymerases (Pol) II, IV, and V being individually or simultaneously knocked out. We found that <i>N</i>²-Et-dG is slightly less blocking to DNA replication than the <i>N</i>²-Bu-dG lesions, which display very similar replication bypass efficiencies. Additionally, Pol II and, to a lesser degree,2021-01-01T00:00:00Z2021 Mar2025-04-18T15:11:05.502Z2025-02-18T23:35:40.279ZS-EPMC79653573341743610.1021/acs.chemrestox.0c00478