Riboregulation in Escherichia coli: DsrA RNA acts by RNA:RNA interactions at multiple loci.
DsrA is an 87-nt untranslated RNA that regulates both the global transcriptional silencer and nucleoid protein H-NS and the stationary phase and stress response sigma factor RpoS (sigmas). We demonstrate that DsrA acts via specific RNA:RNA base pairing interactions at the hns locus to antagonize H-NS translation. We also give evidence that supports a role for RNA:RNA interactions at the rpoS locus to enhance RpoS translation. Negative regulation of hns by DsrA is achieved by the RNA:RNA interaction blocking translation of hns RNA. In contrast, results suggest that positive regulation of rpoS by DsrA occurs by formation of an RNA structure that activates a cis-acting translational operator. Sequences within DsrA complementary to three additional genes, argR, ilvIH, and rbsD, suggest that DsrA is a riboregulator of gene expression that acts coordinately via RNA:RNA interactions at multiple loci.
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Molecular Genetics Program, Wadsworth Center, New York State Department of Health, and School of Public Health, State University of New York at Albany, P.O. Box 22002, Albany, New York 12201-2002, USA.
Cusick
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Belfort
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D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D012808:Sigma Factor / Q000235:genetics
D001426:Bacterial Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; C031908:H-NS protein, bacteria; D012329:RNA, Bacterial; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria