title: Repair and replication of oxidized DNA bases using modified oligodeoxyribonucleotides.
abstract: Modified oligodeoxyribonucleotides (ODNs) are powerful tools to assess the biological significance of oxidized lesions to DNA. For this purpose, we developed original synthetical pathways for the site-specific insertion of several oxidized bases into DNA fragments. Thus, the chemical solid-phase synthesis of ODNs using original strategies of protection and mild conditions of deprotection, as well as a specific post-oxidation approach of an unique nucleoside residue within the sequence have been applied. These two approaches of preparation allowed us to have access to a set of modified ODNs that contain a single modified nucleoside, i.e., N-(2-deoxy-beta-D-erythro-pentofuranosyl)formylamine (dF), 5-hydroxy-2'-deoxycytidine (5-OHdCyd), thymidine glycol (dTg), 5,6-dihydrothymidine (DHdThd), 2,2-diamino-4-[(2-deoxy-beta-D-erythro-pentofuranosyl)-amino]-5(2H)- oxazolone (dZ), N-(2-deoxy-beta-D-erythro-pentofuranosyl)cyanuric acid (dY), 5',8-cyclo-2'-deoxyguanosine (cyclodGuo) and 5',8-cyclo-2'-deoxyadenosine (cyclodAdo). The substrates were used to investigate recognition and removal of the lesions by bacterial DNA N-glycosylases, including endonuclease III (endo III) and Fapy glycosylase (Fpg). In addition, the DNA polymerase-mediated nucleotide incorporation opposite the damage was determined using modified ODNs as templates.
authors.affiliation: Laboratoire Lésions des Acides Nucléiques, C.E.A-Grenoble, France.
authors.forename: D
authors.initials: D
authors.lastname: Gasparutto
authors.forename: A G
authors.initials: AG
authors.lastname: Bourdat
authors.forename: C
authors.initials: C
authors.lastname: D'Ham
authors.forename: V
authors.initials: V
authors.lastname: Duarte
authors.forename: A
authors.initials: A
authors.lastname: Romieu
authors.forename: J
authors.initials: J
authors.lastname: Cadet
mesh_terms: D020029:Base Pairing; D004247:DNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D045647:DNA Glycosylases; D004260:DNA Repair; D004261:DNA Replication / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics; D009699:N-Glycosyl Hydrolases / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000235:genetics; D010084:Oxidation-Reduction; D013379:Substrate Specificity
chemical_list: D009838:Oligodeoxyribonucleotides; D004247:DNA; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases