Cotransduction of strA and ribosomal protein cistrons in Escherichia coli-Salmonella typhimurium hybrids

Comparative chemistry of 30S ribosomal proteins of Salmonella typhimurium

Individual proteins from the 30S ribosome of Salmonella typhimurium were isolated and compared with their counterparts in Escherichia coli. Amino acid composition data reveal either no significant differences, or only minor differences in a few residues between paired proteins. Tryptic peptide fingerprints were used to amplify any possible differences between protein pairs.

Analysis for antigenic similarities among the 30S ribosomal proteins of Escherichia coli

Antiserum was made against a single 30S protein, 30S-7. The amount of complement fixed by total 30S protein in the presence of this antiserum indicated that protein 30S-7 was the major antigen in the mixture of proteins. Each of the 30S ribosomal proteins was tested for cross-reactivity with anti-30S-7. This was done by determining if any of the other 30S proteins inhibited complement fixation by 30S-7. None of the other 30S proteins was found to inhibit complement fixation by 30S-7, indicating that 30S-7 is antigenically distinct from the other proteins.