Some properties of a membrane-deoxyribonucleic acid complex isolated from Bacillus subtilis.

Membrane-deoxyribonucleic acid (DNA) complexes were isolated from Bacillus subtilis by affinity for magnesium-Sarkosyl crystals. These complexes (M-bands) contained greater than 80% of the total cellular DNA; little of the remaining portion could be recovered in a secondary isolation. Isotopic labeling of the origin of replication showed this region of the chromosome to be closely associated with the cell membrane. Interruption of protein or DNA synthesis did not result in detachment of the chromosome from the membrane. Interruption of ribonucleic acid synthesis by rifampin resulted in a decreased ability to isolate DNA in the M-band. Analysis of attachment of the chromosome to membrane during the cell and replication cycles indicated that the chromosome is not released from the membrane at any time during the cell cycle.