Two‐dimensional polyacrylamide gel electrophoresis of proteins synthesized during early germination of Bacillus subtilis 168 in the presence of actinomycin D

Two-dimensional gel electrophoresis was used to demonstrate the synthesis of approximately 65 [35S]-methionine-labelled soluble proteins between 0 and 10 min after the start of germination, of approximately 210 proteins at 10–20 min, and of approximately 260 proteins during vegetative growth of Bacillus subtilis. When actinomycin d and [35S]-methionine were administered at the onset of germination and the proteins synthesized during the subsequent 15 imn were analyzed, two proteins were detected, and were designated protein I and protein II. Immunoblot analysis with an antiserum raised against RNA polymerase from Escherichia coli demonstrated that protein II corresponded to the σA factor of Bacillus subtilis. Thus, the σA facter is synthesized during early germination of Bacillus subtilis in the presence of actinomycin D.