title: Dissecting the differences between the alpha and beta anomers of the oxidative DNA lesion FaPydG.
abstract: The oxidative DNA lesion, FaPydG rapidly anomerizes to form a mixture of the alpha and beta anomer. To investigate the mutagenic potential of both forms, we prepared stabilized bioisosteric analogues of both configurational isomers and incorporated them into oligonucleotides. These were subsequently used for thermodynamic melting-point studies and for primer-extension experiments. While the beta compound, in agreement with earlier data, prefers cytidine as the pairing partner, the alpha compound is not able form a stable base pair with any natural base. In primer-extension studies with the high-fidelity polymerase Bst Pol I, the polymerase was able to read through the lesion. The beta compound showed no strong mutagenic potential. The alpha compound, in contrast, strongly destabilized DNA duplexes and also blocked all of the tested DNA polymerases, including two low-fidelity polymerases of the Y-family.
authors.affiliation: Center for Integrative Protein Science, Department of Chemistry and Biochemistry, Ludwig-Maximilians University Munich, Butenandtstrasse 5-13, Haus F, 81377 Munich, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Büsch
authors.forename: J Carsten
authors.initials: JC
authors.lastname: Pieck
authors.forename: Matthias
authors.initials: M
authors.lastname: Ober
authors.forename: Johannes
authors.initials: J
authors.lastname: Gierlich
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Hsu
authors.forename: Lorena S
authors.initials: LS
authors.lastname: Beese
authors.forename: Thomas
authors.initials: T
authors.lastname: Carell
mesh_terms: D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D004256:DNA Polymerase I / Q000737:chemistry; D004261:DNA Replication; D019075:Electrophoresis, Capillary; D009690:Nucleic Acid Conformation; D010084:Oxidation-Reduction; D011743:Pyrimidines / Q000737:chemistry*; D013237:Stereoisomerism; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D011743:Pyrimidines; C071023:2,6-diamino-4-hydroxy-5-formamidopyrimidine; D004247:DNA; D004256:DNA Polymerase I