Genetic studies of the ribosomal proteins in Escherichia coli. X. Mapping of the ribosomal proteins, L21 and S15, by intergeneric mating experiments between Serratia marcescens and Escherichia coli K12.

Episomes of E. coli, which cover argG but not the str region, were transferred to Serratia marcescens. Ribosomal proteins from these hybrid strains were analyzed with phospho-cellulose or carboxy-methyl-cellulose column chromatography. Two E. coli ribosomal proteins, L21 and S15, could be detected in the ribosome from the hybrid strains in addition to the ribosomal proteins of S. marcescens.