Studies on Protease Sensitive Transfecting DNA of Bacillus Phage
The results of physical analysis of DNA indicated that transfective DNA of Bacillus phage Ø29 bound a protein (1). This DNA-protein complex was further analyzed with labelled DNA (3H)-protein (35S of 14C). The profile of density distribution of this complex gave a single peak in CsC1 density centrifugation. When the DNA was separated into single stranded molecules, a protein was still bound to both strands. The peak of the DNA in CsC1 centrifugation shifted to heavy positions either by trypsin or by S1 (single-endonuclease) treatment. Thus treated DNA lost their transfecting actibity. Sedimentation patterns of the DNA in sucrose density centrifugation did not alter at the main peak before and after trypsin treatment (1).