Competence mutants. II. Physical and biological fate of donor transforming deoxyribonucleic acid.
Transformation-deficient (com(-)) mutants, which are able to bind donor transforming deoxyribonucleic acid (DNA) without yielding a significant number of transformants, were studied with regard to the fate of donor DNA. In no case was there any detectable degradation into acid-soluble radioactivity after donor DNA uptake. Physical experiments showed that some of these mutants are deficient in their ability to associate donor DNA with the recipient's chromosome (dad(-) mutants, for donor association defective), whereas others are able to form what appear to be normal donor-recipient complexes. In spite of physical evidence for integration, none of the dad(-) mutants contains biologically active recombinant DNA, suggesting that they might be deficient in the recombination process (dab(-) mutants, for donor association biologically defective). Donor biological activity is not replicated in any of the mutant strains, and in some cases there is a 10-fold reduction of donor transforming DNA within 60 min after DNA uptake.
D001431:Bacteriological Techniques; D002499:Centrifugation, Density Gradient; D003470:Culture Media; D004269:DNA, Bacterial / Q000378:metabolism; D006193:Haemophilus influenzae / Q000254:growth & development / Q000378:metabolism; D009154:Mutation; D010759:Phosphorus Isotopes; D011995:Recombination, Genetic; D013053:Spectrophotometry; D013395:Sucrose; D013936:Thymidine / Q000378:metabolism; D014170:Transformation, Genetic; D014316:Tritium
D003470:Culture Media; D004269:DNA, Bacterial; D010759:Phosphorus Isotopes; D014316:Tritium; D013395:Sucrose; D013936:Thymidine