1. A dedicated translation factor controls the synthesis of the global regulator Fis.
- Author
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Owens RM, Pritchard G, Skipp P, Hodey M, Connell SR, Nierhaus KH, and O'Connor CD
- Subjects
- 5' Untranslated Regions genetics, Base Sequence, Cell Proliferation, Enzyme Inhibitors pharmacology, Escherichia coli growth & development, Escherichia coli metabolism, Escherichia coli Proteins antagonists & inhibitors, Factor For Inversion Stimulation Protein, GTP Phosphohydrolases antagonists & inhibitors, GTP Phosphohydrolases genetics, Molecular Sequence Data, Molecular Weight, Nucleic Acid Conformation, Phosphoproteins antagonists & inhibitors, Phosphoproteins genetics, Protein Binding, RNA, Messenger chemistry, RNA, Messenger genetics, Ribosomes chemistry, Ribosomes metabolism, Escherichia coli genetics, Escherichia coli Proteins biosynthesis, Escherichia coli Proteins genetics, Escherichia coli Proteins metabolism, GTP Phosphohydrolases metabolism, Gene Expression Regulation, Bacterial, Phosphoproteins metabolism, Protein Biosynthesis, Transcription Factors biosynthesis, Transcription Factors genetics
- Abstract
BipA is a highly conserved protein with global regulatory properties in Escherichia coli. We show here that it functions as a translation factor that is required specifically for the expression of the transcriptional modulator Fis. BipA binds to ribosomes at a site that coincides with that of elongation factor G and has a GTPase activity that is sensitive to high GDP:GTP ratios and stimulated by 70S ribosomes programmed with mRNA and aminoacylated tRNAs. The growth rate-dependent induction of BipA allows the efficient expression of Fis, thereby modulating a range of downstream processes, including DNA metabolism and type III secretion. We propose a model in which BipA destabilizes unusually strong interactions between the 5' untranslated region of fis mRNA and the ribosome. Since BipA spans phylogenetic domains, transcript-selective translational control for the 'fast-track' expression of specific mRNAs may have wider significance.
- Published
- 2004
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