title: UV-radiation-induced formation of DNA bipyrimidine photoproducts in Bacillus subtilis endospores and their repair during germination.
abstract: The spore photoproduct (SP) is the main DNA lesion after UV-C irradiation, and its repair is crucial for the resistance of spores to UV. The aims of the present study were to assess the formation and repair of bipyrimidine photoproducts in spore DNA of various Bacillus subtilis strains using a sensitive HPLC tandem mass spectrometry assay. Strains deficient in nucleotide excision repair, spore photoproduct lyase, homologous recombination (recA), and with wild-type repair capability were investigated. Additionally, one strain deficient in the formation of major small, acid-soluble spore proteins (SASPs) was tested. In all SASP wild-type strains, UV-C irradiation generated almost exclusively SP (>95 %) but also a few by-photoproducts. In the major SASP-deficient strain, SP and by-photoproducts were generated in equal quantities. The status time of 60 min, >75% of the SP was repaired in wild-type strains and in the SASP-deficient strain, while half of the photoinduced SP was removed in the recA-deficient strain. SP-lyase-deficient spores repaired 20% of the SP produced. Thus, SP lyase, with respect to nucleotide excision repair, has a remarkable impact on the removal of SP upon spore germination.
authors.affiliation: German Aerospace Center, Institute of Aerospace Medicine, Radiation Biology Division, Cologne, Germany. ralf.moeller@dlr.de
authors.forename: Ralf
authors.initials: R
authors.lastname: Moeller
authors.forename: Thierry
authors.initials: T
authors.lastname: Douki
authors.forename: Jean
authors.initials: J
authors.lastname: Cadet
authors.forename: Erko
authors.initials: E
authors.lastname: Stackebrandt
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Nicholson
authors.forename: Petra
authors.initials: P
authors.lastname: Rettberg
authors.forename: Günther
authors.initials: G
authors.lastname: Reitz
authors.forename: Gerda
authors.initials: G
authors.lastname: Horneck
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair / Q000502:physiology*; D004269:DNA, Bacterial / Q000378:metabolism / Q000528:radiation effects*; D007700:Kinetics; D011740:Pyrimidine Dimers / Q000378:metabolism* / Q000528:radiation effects; D013171:Spores, Bacterial / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D004269:DNA, Bacterial; D011740:Pyrimidine Dimers