Jerry Simecka2019-08-222019-08-222002-12-012014-04-09https://hdl.handle.net/20.500.12503/29637Weilbacher, Thomas S., A Novel sRNA Member of the Carbon Storage Regulatory System of Escherichi coli. Master of Science (Microbiology & Immunology), December, 2002, 57 pp., 2 tables, 12 illustrations, bibliography, 44 titles. Small untranslated RNAs (sRNAs) perform a variety of important functions in bacterial systems. The 245 nt sRNA of Escherichia coli K-12, CsrC, was uncovered using a genetic screen for genes that regulate glycogen biosynthesis. CsrC RNA binds multiple copies of CsrA, a protein that post-transcriptionally regulates central carbon flux, biofilm formation, and motility in E. coli. CsrC antagonizes the regulatory effects of CsrA, presumably by sequestering this protein. The discovery of CsrC is intriguing, in that a similar sRNA, CsrB, performs essentially the same function. Both of these sRNAs possess similar imperfect repeat sequences (18 in CsrB, 9 in CsrC), primarily localized in the loops of predicted hairpins, which may serve as CsrA binding elements. Transcription of csrC increases as the culture approaches the stationary phase of growth and is activated by CsrA and the response regulator UvrY. Complementation and in vitro transcription-translation experiments reveal that CsrA effects on csrC are mediated indirectly, through UvrY. Because CsrB and CsrC antagonize the activity of CsrA and are dependent on CsrA for their synthesis, a csrB null mutation causes a modest compensatory increase in CsrC levels and vice versa. An updated model for the signaling circuitry of the Csr system is discussed.application/pdfenBacteriaBacterial Infections and MycosesBacteriologyCell AnatomyCell and Developmental BiologyCell BiologyComputational BiologyDevelopmental BiologyDiseasesGeneticsGenetics and GenomicsGenomicsLife SciencesMedical Cell BiologyMedical ImmunologyMedical MicrobiologyMedicine and Health SciencesMicrobiologyMolecular GeneticsOther Cell and Developmental BiologyOther Genetics and GenomicsNovel sRNAcarbon storage regulatory systemE coliEscherichi colisRNAbacterial systemsglycogen biosynthesistranscriptionCsrACsrCrepeat sequencesbinding agentsgrowthresponse regulatorcomplementationin vitrosynthesismutationsignaling circuitryThesis