Influences of a mutated translation initiation factor IF1 or kasugamycin on Escherichia coli gene expression
(English)Manuscript (preprint) (Other academic)
The infA (R40D) mutation or the addition of antibiotic kasugamycin to a wild type strain has been suggested to affect the same related step in translation initiation. Two-dimensional gel electrophoresis of radioactively labeled proteins was used to investigate this effect and to gain an overview of the proteins expressed under these conditions. A number of protein spots with increased or decreased expression levels were identified. The most pronounced increased expression in the IF1 mutant strain were the proteins YbgF (> 5 times) and in the relative abundance of the ribosomal protein S6 (rpsF) isoforms. In the case of kasugamycin treatment strongly increased expression of natural proteins was seen for OppA, GroL, YbgF and several others. Expression of several proteins was affected similarly as a response to either the infA mutation or to the addition of kasugamycin. The translation initiation regions (TIR) comprising a region upstream and downstream of AUG from several of these genes were cloned into the protein A’ reporter gene system for further analysis. TIR sequences of several natural genes that showed elevated expression levels gave a corresponding increase in gene expression as reflected by the protein A’ expression assay system. This is especially true in the case of that the TIR sequence of ybgF gives a strongly increased expression in agreement with the increased expression observed for the native YbgF protein in the infA mutant or upon kasugamycin addition. The results suggest that the TIR region of ybgF has some unique properties that influence its expression at the early translational phase.
E. coli; initiation factor IF1; kasugamycin; 2D-PAGE; initiation region
Microbiology in the medical area Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:su:diva-39299OAI: oai:DiVA.org:su-39299DiVA: diva2:319359