Thymine-containing dimers as well as spore photoproducts are found in ultraviolet-irradiated Bacillus subtilis spores that lack small acid-soluble proteins.
Dormant spores of a Bacillus subtilis mutant that lacks two major small, acid-soluble spore proteins are very sensitive to UV irradiation, which in spores generates about half the amount of thymine-containing dimers formed by comparable irradiation of vegetative cells. Irradiation of mutant spores also produces spore photoproducts, but again only about one-half the amount formed in comparably irradiated wild-type spores. These findings suggest that the high UV sensitivity of the mutant spores is due to the production of pyrimidine dimers, which are not found in UV-irradiated wild-type spores, and that the high level of small, acid-soluble proteins found in wild-type spores is directly involved in spore UV resistance by facilitating a conformational change in spore DNA, preventing pyrimidine dimer formation.
D001412:Bacillus subtilis / Q000235:genetics / Q000528:radiation effects*; D001426:Bacterial Proteins / Q000235:genetics* / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000528:radiation effects; D009154:Mutation; D010777:Photochemistry; D011740:Pyrimidine Dimers / Q000528:radiation effects*; D012995:Solubility; D013171:Spores, Bacterial / Q000528:radiation effects; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D011740:Pyrimidine Dimers