As part of the project aimed at the interaction of RNA with RNA polymerase and primary sigma factor in bacteria we analyzed anti-σ70 antibody immunoprecipitates from Mycobacterium smegmatis stationary phase to identify proteins in σA complex in non-treated cells. We performed mass spectrometry analysis of anti-σ70 antibody and anti-RNAP immunoprecipitates from Corynebacterium glutamicum stationary phase to identify proteins present in σA and RNAP complexes.