Purification and characterization of 30-S ribosomal proteins from Bacillus stearothermophilus

Twenty-three proteins were identified by two-dimensional eletrophoresis on polyacrylamide-gel slabs in the 30-S ribosomal subunit of Bacillus stearothermophilus strain 799. They were designated as B-S1 through B-S21, B-Sa and B-Sb and purified on carboxymethyl-cellulose and Sephadex G100 in the presence of 6 M urea. Their molecular weight was estimated by dodecyl-sulfate-gel electrophoresis and their amino acid composition was determined after acid hydrolysis. Results obtained for the individual proteins were essentially similar to those for Escherichia coli 30-S proteins with some characteristic differences.