title: Effect of 4,5',8-trimethylpsoralen interstrand cross-links present in recipient Bacillus subtilis on the integration of transforming DNA.
abstract: When recipient Bacillus subtilis carrying chromosomal trimethylpsoralen cross-links were transformed, the donor marker activity decreased with the extent of cross-linking. Additional donor marker activity was lost upon incubation of the reextracted DNA with nuclease S1, particularly at higher levels of cross-linking. Physical analysis of the reextracted DNA showed that the donor DNA was progressively excluded from heteroduplex formation as the frequency of cross-links in the recipient DNA increased. In the donor-recipient complexes still being formed, increasing amounts of donor DNA became susceptible to nuclease S1 digestion under these conditions. These results suggest that resident interstrand cross-links interfere both with initiation of recombination and with the completion of heteroduplex formation.
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D002876:Chromosomes, Bacterial / Q000528:radiation effects; D004269:DNA, Bacterial / Q000235:genetics*; D004720:Endonucleases; D011564:Furocoumarins / Q000494:pharmacology*; D007700:Kinetics; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014169:Transformation, Bacterial; D014307:Trioxsalen / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D004269:DNA, Bacterial; D011564:Furocoumarins; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014307:Trioxsalen