Macromolecular synthesis after a nutritional shift-up of Bacillus subtilis

Differences in pattern of a DNA protein complex isolated from vegetative cells and spores of Bacillus subtilis

A DNA protein complex has been isolated from vegetative cells and spores of Bacillus subtilis. Properties of the DNA protein complex prepared from vegetative cells were studied and SDS gel electrophoresis was employed to compare the different DNase-untreated and -treated DNA protein complexes. It is concluded that proteins are associated with the DNA and differences in protein pattern in polyacrylamide gels indicates the involvement of DNA-binding proteins in the regulation of spore formation.

Macromolecular synthesis in chromosome initiation mutants of Bacillus subtilis

Inactivation of the dna B or dna D gene product in Bacillus subtilis stimulates RNA and protein synthesis. Strains containing ts dna B and D mutations have been constructed by introducing the mutations by transformation into a thymine requiring strain which does not lyse during thymine starvation. The consequences of inactivation of these gene products have been assessed by comparing RNA and protein synthesis during thymine starvation at the restrictive temperature with the recipient strain. In the ts+ strain, there is a doubling in rate of RNA synthesis during thymine starvation. In the ts dna B and D mutations at the restrictive temperature the rate of RNA synthesis increases four fold. By preincubating the mutants in the absence of thymine for one generation at the permissive temperature the two fold increase in rate of RNA synthesis associated with inactivation of the initiation complex can be demonstrated under conditions where the ts+ strain shows a decrease in rate of RNA synthesis. The rate of protein synthesis observed largely reflects the rate of RNA synthesis in all strains. Completion of the chromosome at the restrictive temperature has no significant effect on the rate of RNA synthesis. It is suggested that inactivation of the initiation complex after chromosome initiation could play an important role in control of RNA synthesis in relation to the cell cycle.