Altered surface properties of Escherichia coli associated with a specific amino acid change in the S12 ribosomal protein of streptomycin-resistant mutants.

Escherichia coli mutants resistant to streptomycin exhibited differences in countercurrent distribution from the parental strains. The degree of difference from the parental strain correlated with the degree of restriction of translation and thus the particular strA allele. The changes in countercurrent distribution in the phase systems used probably resulted predominantly from surface charge alterations. The differences in countercurrent distribution in these and other mutants may be a useful selective technique to obtain different types of mutants for which specific selective techniques may not be available. In addition, it appears that the surface properties of cells, which determine their position in countercurrent distribution, are a function of the translational efficiency and fidelity, and that the surface of cells consists of a mosaic that is an expression of this translational fidelity.