The small RNA regulators of Escherichia coli: roles and mechanisms*.
Small noncoding RNAs have been found in all organisms, primarily as regulators of translation and message stability. The most exhaustive searches have taken place in E. coli, resulting in identification of more than 50 small RNAs, or 1%-2% of the number of protein-coding genes. One large class of these small RNAs uses the RNA chaperone Hfq; members of this class act by pairing to target messenger RNAs. Among the members of this class are DsrA and RprA, which positively regulate rpoS translation, OxyS, which negatively regulates rpoS translation and fhlA translation, RyhB, which reapportions iron use in the cell by downregulating translation of many genes that encode Fe-containing proteins, and Spot 42, which changes the polarity of translation in the gal operon. The promoters of these small RNAs are tightly regulated, frequently as part of well-understood regulons. Lessons learned from the study of small RNAs in E. coli can be applied to finding these important regulators in other organisms.
Laboratory of Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892, USA. susang@helix.nih.gov.
Susan
S
Gottesman
D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D020029:Base Pairing; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D035001:Host Factor 1 Protein / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis / Q000502:physiology; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D022661:RNA, Untranslated / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D012808:Sigma Factor / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D058727:RNA, Small Untranslated
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D035001:Host Factor 1 Protein; D012329:RNA, Bacterial; D022661:RNA, Untranslated; D012097:Repressor Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C499660:DrsA protein, E coli; C087373:Hfq protein, E coli; C499686:oxyS small RNA, E coli; D058727:RNA, Small Untranslated; C069567:sigma factor KatF protein, Bacteria