title: Repair of DNA containing Fapy.dG and its beta-C-nucleoside analogue by formamidopyrimidine DNA glycosylase and MutY.
abstract: Fapy.dG is produced in DNA as a result of oxidative stress. Under some conditions Fapy.dG is formed in greater yields than 8-oxodG from a common chemical precursor. Recently, Fapy.dG and its C-nucleoside analogue were incorporated in chemically synthesized oligonucleotides at defined sites. Like 8-oxodG, Fapy.dG instructs DNA polymerase to misincorporate dA opposite it in vitro. The interactions of DNA containing Fapy.dG or the nonhydrolyzable analogue with Fpg and MutY are described. Fpg excises Fapy.dG (K(M) = 2.0 nM, k(cat) = 0.14 min(-1)) opposite dC approximately 17-fold more efficiently than when mispaired with dA, which is misinserted by DNA polymerase in vitro. Fpg also prefers to bind duplexes containing Fapy.dG.dC or beta-C-Fapy.dG.dC compared to those in which the lesion is opposite dA. MutY incises dA when it is opposite Fapy.dG and strongly binds duplexes containing the lesion or beta-C-Fapy.dG. Incision from Fapy.dG.dA is faster than from dG.dA mispairs but slower than from DNA containing 8-oxodG opposite dA. These data demonstrate that Fapy.dG closely resembles the interactions of 8-oxodG with two members of the GO repair pathway in vitro. The similar effects of Fapy.dG and 8-oxodG on DNA polymerase and repair enzymes in vitro raise the question as to whether Fapy.dG elicits similar effects in vivo.
authors.affiliation: Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
authors.forename: Carissa J
authors.initials: CJ
authors.lastname: Wiederholt
authors.forename: Michael O
authors.initials: MO
authors.lastname: Delaney
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Pope
authors.forename: Sheila S
authors.initials: SS
authors.lastname: David
authors.forename: Marc M
authors.initials: MM
authors.lastname: Greenberg
mesh_terms: D000225:Adenine / Q000737:chemistry / Q000378:metabolism; D020137:Base Pair Mismatch; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000378:metabolism*; D004249:DNA Damage; D045647:DNA Glycosylases; D004260:DNA Repair; D043382:DNA-Formamidopyrimidine Glycosylase; D003839:Deoxyadenosines / Q000737:chemistry / Q000378:metabolism; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005559:Formamides / Q000737:chemistry / Q000378:metabolism*; D005663:Furans / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D009699:N-Glycosyl Hydrolases / Q000378:metabolism*; D009692:Nucleic Acid Heteroduplexes / Q000235:genetics / Q000378:metabolism; D009705:Nucleosides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011743:Pyrimidines / Q000737:chemistry / Q000378:metabolism*
chemical_list: D003839:Deoxyadenosines; D005559:Formamides; D005663:Furans; C435881:N6-(2-deoxy-erythro-pentofuranosyl)-2,6-diamino-4-hydroxy-5-formamidopyrimidine; D009692:Nucleic Acid Heteroduplexes; D009705:Nucleosides; D011743:Pyrimidines; D004247:DNA; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases; C061738:mutY adenine glycosylase; D043382:DNA-Formamidopyrimidine Glycosylase; D003849:Deoxyguanosine; D000225:Adenine