Reconstitution studies show that rifampicin resistance is determined by the largest polypeptide of Bacillus subtilis RNA polymerase.

A procedure has been developed to separate the subunits of Bacillus subtilis RNA polymerase rapidly and in good yield. The method involved the use of a blue dextran-Sepharose column which bound the beta' subunit. A phosphocellulose column was used to separate the alpha and beta subunits. During purification, the enzyme eluted from the DNA-cellulose column in three separate forms in the order alpha2betabeta'deltaomega1,alpha2betabeta'omega1, and alpha2betabeta'omega1sigma. Subunit reconstitution studies with RNA polymerase subunits from wild type and a rifampicin-resistant mutant indicated that the largest polypeptide was responsible for rifampicin resistance. Thus, this subunit is referred to as beta. The mobility of the subunits in sodium dodecyl sulfate-polyacrylamide gel electrophoresis cannot be used as the sole criterion for designating the functions of the subunits of RNA polymerase.     

The specificity in promoter recognition by the Bacillus subtilis RNA polymerase deltaA and deltaH holoenzymes is connected with periodicities in the promoter nucleotide sequences

Promoters recognized by deltaA-RNA and deltaH-RNA polymerase have different periodic patterns their nucleotide disposition. By using the special method of Fourier analysis for symbolic sequences. Fourier spectra of the primary structure of promoters transcribed bv deltaA-RNA and deltaH-RNA polymerase were obtained. For two data sets, a small one and a big one, a stepwise discriminant analysis with jackknife test based on the spectral characteristics of each of the promoters was performed. It was shown that it is possible to classify the data with the accuracy of 100% sets into classes: promoters that are recognized by the deltaA-RNA polymerise and promoters that are recognized by the deltaH-RNA polymerase. Significant correlations between the promoter strength and the characteristics of their Fourier spectra were obtained. Thus, the periodicity in nucleotide distribution along the polynucleotide chain is the attribute sufficient for promoter recognition by RNA polymerase holoenzyme.