Translational repression mechanisms in prokaryotes.
Translational repression results from a complex choreography of macromolecular interactions interfering with the formation of translational initiation complexes. The relationship between the rate and extent of formation of these interactions to form repressed mRNA complexes determines the extent of repression. A novel analysis of repression mechanisms is presented here and it indicates that the reversibility of repressed complex formation influences the steady state balance of the distribution of translationally active and inactive complexes and therefore has an impact on the efficiency of repression. Reviewed here is evidence for three distinct translational repression mechanisms, regulating expression of the transcription factor sigma32, threonine tRNA synthetase and ribosomal proteins on the alpha operon in Escherichia coli. Efficient regulation of expression in these systems makes use of specific mRNA structures in quite different ways.
Schlax
Paula Jean
PJ
Department of Chemistry, Program in Biological Chemistry, Bates College, 5 Andrews Road, Lewiston, Maine 04240, USA. pschlax@bates.edu
Worhunsky
David J
DJ
D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000378:metabolism; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism; D012808:Sigma Factor; D013914:Threonine-tRNA Ligase / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D012269:Ribosomal Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C069774:heat-shock sigma factor 32; D013914:Threonine-tRNA Ligase