Studies on the nature of replicating DNA in T4-infected Escherichia coli

摘要: The replicating DNA of T4-infected Escherichia coli has been isolated as a rapidly sedimenting structure about 200 s at 15 minutes after infection. This sedimentation, rate is approached from smaller values earlier times Several properties suggest that it differs ordinary molecules phage or nonspecific aggregates DNA. very fragile breaks into products sediment like but are less homogeneous and appear to be more sensitive further breakage than Treatment with nucleases act on denatured results in the simultaneous formation intermediate material heterogeneous fragments ranging 30 100 s. An early hydrolysis product sediments 73 latter resembles fraction recovered chloramphenicol-treated infected cells ( Frankel, 1963 ). buoyant density CsCl almost identical After recovery same band, two DNA's retain, part, their difference sedimentation rate. thermal denaturation DNA, complete densities identical. Preliminary experiments polynucleotide strands not longer those It concluded T4 state different mature former may could contain all newly synthesized single, bizarre structure. would possess regions which usual base pairing native interrupted. Other structures, however, excluded.