title: Structural and dynamic effects of single 7-hydro-8-oxoguanine bases located in a frameshift target DNA sequence.
abstract: DNA 7-hydro-8-oxoguanine (8-oxoG) is implicated in frameshift formation in an G(6) sequence of the HPRT gene in mismatch repair (MMR) defective cells. Using oligonucleotides based on this frameshift hotspot, we investigated how a single 8-oxoG modified the structural and dynamic properties of the G(6) tract. A 30 ns molecular dynamics (MD) simulation indicated compression of the minor groove in the immediate vicinity of the lesion. Fluorescence polarization anisotropy (FPA) and MD demonstrated that 8-oxoG increases DNA torsional rigidity and also constrains the movement of the single-stranded region at the single/double stranded DNA junction of model DNA replication template/primer. These constraints influenced the efficiency of primer extension by Klenow (exo(-)) DNA polymerase.
authors.affiliation: Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Rome, Italy.
authors.forename: Flavia
authors.initials: F
authors.lastname: Barone
authors.forename: Filip
authors.initials: F
authors.lastname: Lankas
authors.forename: Nada
authors.initials: N
authors.lastname: Spackova
authors.forename: Jiri
authors.initials: J
authors.lastname: Sponer
authors.forename: Peter
authors.initials: P
authors.lastname: Karran
authors.forename: Margherita
authors.initials: M
authors.lastname: Bignami
authors.forename: Filomena
authors.initials: F
authors.lastname: Mazzei
mesh_terms: D020137:Base Pair Mismatch; D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D004260:DNA Repair; D004261:DNA Replication / Q000187:drug effects*; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism; D005454:Fluorescence Polarization; D006147:Guanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D009690:Nucleic Acid Conformation / Q000187:drug effects*; D013698:Templates, Genetic
chemical_list: C024829:8-hydroxyguanine; D006147:Guanine; D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase; D004259:DNA-Directed DNA Polymerase