Regulation of Transcription during Sporulation of Bacillus cereus T. DNA-Dependent RNA Polymerase from Vegetative and Sporulating Cells

DNA-dependent RNA polymerase from vegetative cells of Bacillus cereus T was purified to homogeneity by poly(ethyleneimine) precipitation, elution and DNA affinity chromatography. The purified enzyme shows high activity on the DNA of B. cereus phage øCL. The subunit composition (ββ′α2)σ, corresponds to the RNA polymerase of other prokaryotes. The molecular weights of the subunits are: β 140000, β′ 130000, α 43000, σ 56000. The σ factor can be separated from core enzyme by phosphocellulose chromatography. Both isolated σ factor, and the ασ fraction isolated from complete enzyme by cellogel electrophoresis, stimulate the activity of core enzyme on øCL DNA. Enzymes isolated from sporulating cells at 1.5, 3 and 12 h after the end of logarithmic growth did not differ from vegetative enzyme in their subunit patterns and no change in template specificity could be found.