RNA polymerase heterogeneity in Streptomyces aureofaciens: characterization by antibody-linked polymerase assay.

Using antibody-linked polymerase assay we studied the polypeptide composition of DNA-dependent RNA polymerase from Streptomyces aureofaciens and immunological cross-reaction with Escherichia coli RNA polymerase. We identified about 25 'ALPA-reactive' polypeptides which are probably involved in the transcriptional apparatus. We demonstrated that beta' and beta subunits from S. aureofaciens and E. coli are immunologically related and sigma70 (E. coli) shows immunochemical similarity with sigma35 (S. aureofaciens). According to the reconstitution of RNA polymerase holoenzyme and antibody-linked polymerase assay we identified sigma factors responsible for recognition of two promoters.