This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Mizuno, T Articles by Mizushima, S Search for Related Content PubMed PubMed Citation Articles by Mizuno, T Articles by Mizushima, S

 Previous Article  |  Next Article 

J Bacteriol. 1976 February; 125(2): 524-530

Coordinated alterations in ribosomes and cytoplasmic membrane in sucrose-dependent, spectinomycin-resistant mutants of Escherichia coli.

ABSTRACT

Alterations in cytoplasmic membrane and ribosomes from sucrose-dependent spectinomycin-resistant (Sucd-Spcr) mutants of Escherichia coli, mutants that are resistant to spectinomycin in the presence of 20% sucrose but sensitive in the absence of sucrose, were studied. The protein composition of cytoplasmic membrane was analyzed by gel electrophoresis on polyacrylamide gel containing 8 M urea and 0.5% sodium dodecyl sulfate, which assured the reproducible separation of 28 protein bands. A major protein band, I-19, was missing in all cytoplasmic membrane preparations from 10 Sucd-Spcr mutants. Besides protein I-19, proteins I-13 and I-24 were missing in some mutants. On the other hand, the protein composition of cytoplasmic membrane from a sucrose-independent spectinomycin-resistant mutant was indistinguishable from that from the wild-type strain. The polypeptide synthetic activity of ribosomes from Sucd-Spcr mutants was resistant to spectinomycin. Studies on a revertant obtained from one of these mutants without any selection for sensitivity to spectinomycin revealed that a single mutation was responsible for both the ribosomal alteration, i.e., spectinomycin resistance, and the lack of protein I-19 in the cytoplasmic membrane. Studies on a transductant obtained with a Sucd-SPcr mutant as the donor also confirmed the single-mutation concept. It was concluded that in Sucd-SPcr mutants an alteration in the ribosomes caused the deletion of protein I-19 from cytoplasmic membrane.