Defective Bacteriophage PBSH in Bacillus subtilis: III. Properties of Adenine-16 Marker in Purified Bacteriophage Deoxyribonucleic Acid.

The adenine-16 (ade-16) marker (the marker nearest the chromosomal origin of Bacillus subtilis) in purified PBSH deoxyribonucleic acid (DNA) renatured more rapidly and to a greater extent than any other marker in the phage DNA, and more rapidly and to a greater extent than all markers, including ade-16, in bacterial DNA. The renaturation of the phage DNA ade-16 marker followed a first-order reaction, whereas renaturation of bacterial markers was initially a second-order reaction. No cross-linkages were detected in DNA molecules containing the ade-16 marker. Buoyant density measurements and inactivation by heat and micrococcal deoxyribonuclease of the ade-16 marker did not reveal large segments of clusters of the individual bases in these molecules. Alternative mechanisms for the unique renaturation behavior of the ade-16 marker are discussed.