title: Characterization of a novel DNA glycosylase from S. sahachiroi involved in the reduction and repair of azinomycin B induced DNA damage.
abstract: Azinomycin B is a hybrid polyketide/nonribosomal peptide natural product and possesses antitumor activity by interacting covalently with duplex DNA and inducing interstrand crosslinks. In the biosynthetic study of azinomycin B, a gene (orf1) adjacent to the azinomycin B gene cluster was found to be essential for the survival of the producer, Streptomyces sahachiroi ATCC33158. Sequence analyses revealed that Orf1 belongs to the HTH_42 superfamily of conserved bacterial proteins which are widely distributed in pathogenic and antibiotic-producing bacteria with unknown functions. The protein exhibits a protective effect against azinomycin B when heterologously expressed in azinomycin-sensitive strains. EMSA assays showed its sequence nonspecific binding to DNA and structure-specific binding to azinomycin B-adducted sites, and ChIP assays revealed extensive association of Orf1 with chromatin in vivo. Interestingly, Orf1 not only protects target sites by protein-DNA interaction but is also capable of repairing azinomycin B-mediated DNA cross-linking. It possesses the DNA glycosylase-like activity and specifically repairs DNA damage induced by azinomycin B through removal of both adducted nitrogenous bases in the cross-link. This bifunctional protein massively binds to genomic DNA to reduce drug attack risk as a novel DNA binding protein and triggers the base excision repair system as a novel DNA glycosylase.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Le
authors.initials: L
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: LiYuan
authors.initials: L
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: FeiXue
authors.initials: F
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: ShengQing
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University Helmholtz Joint Institute of Biotechnology, School of Life Science, Shandong University, Jinan 250100, China.
authors.forename: AiYing
authors.initials: A
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China hejingjj@mail.hzau.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: He
mesh_terms: D000900:Anti-Bacterial Agents / Q000633:toxicity; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D019295:Computational Biology; D004249:DNA Damage / Q000187:drug effects*; D045647:DNA Glycosylases / Q000378:metabolism*; D004260:DNA Repair; D004268:DNA-Binding Proteins; D024881:Drug Resistance, Bacterial / Q000235:genetics; D017353:Gene Deletion; D023061:Gene Order; D036341:Intercellular Signaling Peptides and Proteins; D008954:Models, Biological; D009281:Naphthalenes / Q000633:toxicity; D010455:Peptides / Q000633:toxicity*; D011485:Protein Binding; D013302:Streptomyces / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002843:Chromatin; D004268:DNA-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; D009281:Naphthalenes; D010455:Peptides; C051055:azinomycin B; D045647:DNA Glycosylases