The phrA gene of Rhodobacter sphaeroides encodes a photolyase and is regulated by singlet oxygen and peroxide in a sigma(E)-dependent manner.
The genome of the facultatively photosynthetic bacterium Rhodobacter sphaeroides encodes three proteins of the photolyase/cryptochrome family. This paper shows that phrA (RSP2143) encodes a functional photolyase, which is an enzyme that repairs UV radiation-induced DNA damage in a blue light dependent manner. Expression of phrA is upregulated in response to light, with no photoreceptor or the photosynthetic electron transport being involved. The results reveal that singlet oxygen and hydrogen peroxide dependent signals are transmitted by the sigma(E) factor and the anti-sigma(E) factor ChrR affecting phrA expression, while superoxide anions do not stimulate phrA expression. Thus, the sigma(E) regulon is involved not only in the response to singlet oxygen but also in the hydrogen peroxide response.
Hendrischk
Anne-Kathrin
AK
Institut für Mikrobiologie und Molekularbiologie, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.
Braatsch
Stephan
S
Institut für Mikrobiologie und Molekularbiologie, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.
Glaeser
Jens
J
Institut für Mikrobiologie und Molekularbiologie, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.
Klug
Gabriele
G
Institut für Mikrobiologie und Molekularbiologie, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000502:physiology; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000096:biosynthesis / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D017930:Genes, Reporter; D008027:Light; D050296:Microbial Viability; D008969:Molecular Sequence Data; D010545:Peroxides / Q000494:pharmacology*; D012242:Rhodobacter sphaeroides / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D012808:Sigma Factor / Q000037:antagonists & inhibitors / Q000502:physiology*; D026082:Singlet Oxygen / Q000494:pharmacology*; D013481:Superoxides / Q000494:pharmacology; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000502:physiology*; D015854:Up-Regulation; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C093117:ChrR protein, Rhodobacter sphaeroides; D010545:Peroxides; D012808:Sigma Factor; D014157:Transcription Factors; C063202:sporulation-specific sigma factors; D013481:Superoxides; D026082:Singlet Oxygen; D001616:beta-Galactosidase; D004255:Deoxyribodipyrimidine Photo-Lyase