Oxygen induces mutation in a strict anaerobe, Prevotella melaninogenica.
Strict anaerobes are highly sensitive to oxygen, but the mutagenicity of oxygen in strict anaerobes has not been well understood. Prevotella melaninogenica, a strict anaerobe, is susceptible to oxygen and shows an increase in oxidative DNA damage upon exposure to oxygen. In this study, we have investigated the mutagenicity of oxygen and the types of mutations induced by oxygen. Exposure to oxygen decreased cell survival and increased the levels of 8-oxo-deoxyguanosine (8-oxodG). The frequency of rifampicin-resistant mutants was markedly increased after exposure to oxygen. After sequencing a 254-bp fragment of the rpoB gene, which encodes the beta subunit of bacterial RNA polymerase, a target molecule of rifampicin, we found that most mutants induced by oxygen had GC to TA transversions, a signature of 8-oxodG. In addition, all detected single-nucleotide changes would lead to amino acid changes that confer rifampicin resistance. These results indicate that oxygen is mutagenic in a strict anaerobe, P. melaninogenica, and its mutagenic characteristics could be analyzed with this experimental system.
Takumi
Shota
S
Department of Environmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, 890-8544 Kagoshima, Japan.
Komatsu
Masaharu
M
Aoyama
Kohji
K
Watanabe
Kunitomo
K
Takeuchi
Toru
T
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000595:Amino Acid Sequence; D000904:Antibiotics, Antitubercular / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010100:Oxygen / Q000502:physiology*; D001443:Prevotella melaninogenica / Q000235:genetics / Q000378:metabolism*; D012293:Rifampin / Q000494:pharmacology
D000904:Antibiotics, Antitubercular; D001426:Bacterial Proteins; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine; D010100:Oxygen; D012293:Rifampin