title: Kinetic analysis of bypass of O(6)- methylguanine by the catalytic core of yeast DNA polymerase eta.
abstract: Alkylating agents can form O(6)-methylguansine (O(6)-MeG). To study the intrinsic kinetic behaviors of bypassing O(6)-MeG, we used the catalytic core of yeast DNA polymerase η (Pol ηcore, residues 1-513), instead of the full-length Pol η, to study their elementary steps, eliminating the effects of the C-terminal C2H2 motif on dNTP incorporation. The misincorporation frequencies were 10(-4) for G and 0.055-0.446 for O(6)-MeG. O(6)-MeG does not affect the extension efficiency. Pol ηcore showed no fast burst phase for any incorporation opposite G or O(6)-MeG. Primer extension was greatly blocked by O(6)-MeG and about 67% dTTP, 31% dCTP and 2% dATP were incorporated opposite O(6)-MeG. This study provides further understanding of the mutation mechanism of alkylated lesion for yeast DNA polymerase η.
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China.
authors.forename: Binyan
authors.initials: B
authors.lastname: Liu
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China.
authors.forename: Qizhen
authors.initials: Q
authors.lastname: Xue
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China.
authors.forename: Shiling
authors.initials: S
authors.lastname: Gu
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Wang
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China.
authors.forename: Yingqing
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
authors.forename: Chunxue
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China. Electronic address: huidongzhang@tmmu.edu.cn.
authors.forename: Huidong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D020816:Amino Acid Motifs; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry* / Q000235:genetics; D003854:Deoxyribonucleotides / Q000737:chemistry; D006147:Guanine / Q000031:analogs & derivatives* / Q000737:chemistry; D007700:Kinetics; D000072417:Protein Domains; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D000099270:Y-Family DNA Polymerases
chemical_list: D004259:DNA-Directed DNA Polymerase; D003854:Deoxyribonucleotides; D006147:Guanine; C008449:O-(6)-methylguanine; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases
keywords: Kinetics; O(6)-MeG; Pre-steady-state; Yeast DNA polymerase η; dNTP incorporation