Ribosomal proteins from streptomycin-resistant and dependent mutants, and revertants from streptomycin-dependence to independence in Bacillus subtilis.

Streptomycin-resistant and dependent mutants were isolated from Bacillus subtilis ATCC 6633. Ribosomal proteins were analysed from six such mutants with chromatography on carboxymethyl cellulose or phosphocellulose columns. An altered specific 30s ribosomal protein, 30B, could be detected in all of these mutants. Streptomycin-independent revertants were isolated from a streptomycin-dependent strain. Some of them had an altered 30s ribosomal protein, 30A, and some others had an altered 30C protein. It was shown that from the data of partial N-terminal amino acid sequences together with amino acid compositions and mobilities on two-dimensional gel electrophoresis of these proteins that 30A, 30B, and 30C proteins were homologous with S5, S12 and S4 of E. coli 30s ribosomal proteins, respectively.