A mutant of Escherichia coli strain K12S isolated after selection for resistance to the amino
glycoside antibiotic neamine shows severe restriction of amber suppressors in vivo.
Ribosomes from the mutant exhibit low neamine-induced misreading in vitro and a
decreased affinity for the related antibiotic streptomycin. The S17 ribosomal protein from the
mutant strain shows altered electrophoretic mobility on two-dimensional polyacrylamide gels
and also differs in chromatographical behaviour from the S17 protein from the parental …

A mutant of Escherichia coli strain K12S, nea R 301, resistant to the antibiotic neamine was
found to have an altered 30 S ribosomal protein S17. The modification involves a change in
the electrophoretic mobility of this protein. S17 proteins wore purified from the mutant and
the parental strain, respectively, and the amino acid compositions of all tryptic peptides were
compared. The results show that the mutational alteration involves a replacement of
histidine by proline in peptide T8 from mutant nea R 301. The amino acid replacement is …