A dedicated translation factor controls the synthesis of the global regulator Fis.
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.
School of Biological Sciences, University of Southampton, Southampton, UK.
Róisín M
RM
Owens
Gareth
G
Pritchard
Paul
P
Skipp
Michelle
M
Hodey
Sean R
SR
Connell
Knud H
KH
Nierhaus
C David
CD
O'Connor
D020121:5' Untranslated Regions / Q000235:genetics; D001483:Base Sequence; D049109:Cell Proliferation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism*; D035021:Factor For Inversion Stimulation Protein; D020558:GTP Phosphohydrolases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D010750:Phosphoproteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics*
D020121:5' Untranslated Regions; D004791:Enzyme Inhibitors; D029968:Escherichia coli Proteins; D035021:Factor For Inversion Stimulation Protein; C501034:Fis protein, E coli; D010750:Phosphoproteins; D012333:RNA, Messenger; D014157:Transcription Factors; D020558:GTP Phosphohydrolases; C408370:typA protein, E coli