title: Mutation spectrum induced by dihydropyrazines in Escherichia coli.
abstract: Dihydropyrazine (DHP), which induces mutagenesis in E. coli, was investigated. From analyzing mutations in the chromosomal rpoB gene, the mutation spectrum in uvrB strain revealed the different behavior on exposure to two DHP derivatives 3-hydro-2,2,5,6-tetramethylpyrazine (HTMP), and 2,3-dihydro-5,6-dimethylpyrazine (DHDMP). A higher level of DHP-induced mutation was observed, with base substitutions at G : C pairs predominant. HTMP and DHDMP increased the frequency of G : C to T : A transversions. HTMP increased the frequency of G : C to A : T transitions, than did DHDMP. These findings suggest that DHPs prefer to attack the G : C pair and that different DHP derivatives may prefer distinct mutagenic base pairs; and further, that nucleotide excision repair may be involved in the repair of DHP-induced mutations.
authors.affiliation: Faculty of Pharmaceutical Sciences, Sojo University Kumamoto, Japan. stakechi@ph.sojo-u.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Takechi
authors.forename: Tadatoshi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Hajime
authors.initials: H
authors.lastname: Nomura
authors.forename: Toshio
authors.initials: T
authors.lastname: Minematsu
authors.forename: Masaru
authors.initials: M
authors.lastname: Adachi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kurata
authors.forename: Rie
authors.initials: R
authors.lastname: Kurata
mesh_terms: D000904:Antibiotics, Antitubercular / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D004265:DNA Helicases / Q000235:genetics; D004252:DNA Mutational Analysis; D004260:DNA Repair / Q000187:drug effects; D004269:DNA, Bacterial / Q000096:biosynthesis / Q000235:genetics; D012321:DNA-Directed RNA Polymerases; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics; D016296:Mutagenesis; D009153:Mutagens / Q000138:chemical synthesis / Q000494:pharmacology*; D009154:Mutation / Q000187:drug effects*; D011719:Pyrazines / Q000494:pharmacology*; D012293:Rifampin / Q000494:pharmacology
chemical_list: D000904:Antibiotics, Antitubercular; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D009153:Mutagens; D011719:Pyrazines; C058093:UvrB protein, E coli; C483832:rpoB protein, Streptococcus pneumoniae; D012321:DNA-Directed RNA Polymerases; D004265:DNA Helicases; D012293:Rifampin