SINGLE‐STRAND BREAKS INDUCED IN BACILLUS SUBTILIS DNA BY ULTRAVIOLET LIGHT: ACTION SPECTRUM and PROPERTIES

摘要: — The induction of single-strand breaks (alkali-labile bonds plus frank breaks) in the DNA Bacillus subtilis irradiated vivo by monochromatic UV light at wavelengths from 254 to 434 nm was measured. spectrum consists a major far-UV (below 320 nm) component and minor near-UV shoulder. A mutant deficient polymerase I accumulates caused (above faster than wild-type strain proficient I. Measurable extracted are induced higher frequency those vivo. Anoxia, glycerol, diazobicyclo (2.2.2.) octane inhibit break formation DNA. Alkali-labile 365-nm radiation largely (78%) covalent bond chain breaks, remainder true alkali-labile bonds, probably apurinic apyrimidinic sites.