Copurification of ribosomal protein S2 and DNA-dependent RNA polymerase from heat-shocked cells of Bacillus subtilis.

The DNA-dependent RNA polymerases from heat-shocked and vegetatively grown cells of Bacillus subtilis were isolated and compared. The RNA polymerase from non-stressed cells had the well known alpha, beta, beta' and sigma composition of eubacterial RNA polymerases. The RNA polymerase from heat-shocked cells exhibited one additional band shown by SDS-PAGE. N-terminal sequencing of the first 16 amino acids of the associated protein demonstrated its identity with the ribosomal protein S2.