The nucleotide sequences of Bacillus stearothermophilus ribosomal protein S12 and S7 genes: comparison with the str operon of Escherichia coli.

The primary structure of the ribosomal protein S7 from Bacillus stearothermophilus (BstS7) was analyzed by a combination of amino acid and DNA sequence analysis. Peptide sequence information was derived from tryptic peptides of BstS7 by manual Edman degradation. The nucleotide sequence of the 1.5-kb SalI fragment from B. stearothermophilus genome, cloned by the Escherichia coli S12 gene (rpsL) as a hybridization probe, was determined. Comparison of deduced amino acid sequence with the corresponding sequences of E. coli ribosomal proteins showed that this fragment contains the genes encoding S12, S7, and the N-terminus of the elongation factor G. Thus, the organization of this gene cluster is same as that in the str operon of E. coli. The amino acid sequence of B. stearothermophilus S12 (BstS12) deduced from the nucleotide sequence information agrees with the published amino acid sequence of BstS12 [M. Kimura and J. Kimura, FEBS Lett., 210, 91 (1987)]. The deduced sequence of B. stearothermophilus S7 (BstS7), together with sequence information of tryptic peptides, showed that protein S7 consists of 155 amino acid residues with a calculated molecular weight of 17933 and has 56% amino acid identity with the E. coli S7 (EcoS7).