title: Effects of the N terminus of mouse DNA polymerase κ on the bypass of a guanine-benzo[a]pyrenyl adduct.
abstract: DNA polymerase κ (Polκ), one of the typical member of the Y-family DNA polymerases, has been demonstrated to bypass the 10S(+)-trans-anti-benzo[a]pyrene diol epoxide-N(2)-deoxyguanine adducts (BPDE-dG) efficiently and accurately. A large structural gap between the core and little finger as well as an N-clasp domain are essential to its unique translesion capability. However, whether the extreme N-terminus of Polκ is required for its activity is unclear. In this work, we constructed two mouse Polκ deletions, which have either a catalytic core (mPolκ1-516) or a core without the first 21-residues (mPolκ22-516), and tested their activities in the replication of normal and BPDE-DNA. These two Polκ deletions are nearly as efficient as the full length protein (Polκ1-852) in normal DNA synthesis. However, steady-state kinetics reveals a significant reduction in efficiency of dCTP incorporation opposite the lesion by Polκ22-516, along with increased frequencies for misinsertion compared with Polκ1-852 The next nucleotide insertion opposite the template C immediately following the BPDE-dG was also examined, and the bypass differences induced by deletions were highlighted in both insertion and extension step. We conclude that the extreme N-terminal part of Polκ is required for the processivity and fidelity of Polκ during translesion synthesis of BPDE-dG lesions.
authors.affiliation: Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China liuyang@big.ac.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China liuyang@big.ac.cn guocx@big.ac.cn.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Ma
authors.affiliation: Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China guocx@big.ac.cn.
authors.forename: Caixia
authors.initials: C
authors.lastname: Guo
mesh_terms: D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D020134:Catalytic Domain / Q000235:genetics; D018736:DNA Adducts / Q000378:metabolism*; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D003845:Deoxycytosine Nucleotides / Q000378:metabolism; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000737:chemistry; D057075:Enzyme Assays; D007700:Kinetics; D051379:Mice; D016296:Mutagenesis; D000099270:Y-Family DNA Polymerases
chemical_list: D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D018736:DNA Adducts; D004259:DNA-Directed DNA Polymerase; D003845:Deoxycytosine Nucleotides; D003849:Deoxyguanosine; C043931:benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide-DNA; C024107:2'-deoxycytidine 5'-triphosphate; C040060:7,8-dihydroxy-9,10-epoxide-7,8,9,10-tetrahydrobenzo(a)pyrene-10-deoxyguanosine; C498613:Polk protein, mouse; D000099270:Y-Family DNA Polymerases
keywords: BPDE-dG lesions; Y-family DNA polymerase κ; enzyme fidelity; polycyclic aromatic hydrocarbons; translesion DNA synthesis