Peptide maps of regulatory subunits of Bacillus subtilis RNA polymerase

Peptide maps of four regulatory subunits of Bacillus subtilis RNA polymerase were obtained. Three sigma-like proteins (sigma 55, sigma 37, and sigma 29) as well as the transcription modification factor, delta (delta) protein, were shown to give unique peptide patterns. This observation demonstrates that each is a distinct protein species; none is derived from another by a simple proteolytic modification.