Identification of Small Rna's As Novel Regulatory Switches in The Envelope Stress Response in Escherichai Coli

The USDA reports that bacteria are responsible for 39% of reported food-borne illness. E.coli O157:H7 is one of the top five causes of bacterial-related food borne illnesses. The resulting infection can range from mild to severe and huge public health concern.The presence of receptors and surface proteins play a major role in pathogenic E.coli O157 ability to cause infection. The bacterial envelope stress response is trigged when there is perturbation of outer membrane protein. Thepossible post-transcriptional regulation of the RseAP3 transcript by small regulatory RNAs has not been fully investigated.This gap in the current knowledge of RseA regulation provides the basis for this investigation. The primary goal of this project is to investigate the possible post-transcriptional regulation of RseA by small regulatory RNAs (sRNAs). The rationale driving the project goal is the discovery of a relatively long (228 nucleotides) 5' un-translated region of a novel RseA transcript and
the fact that the envelope stress is so tightly regulated.Objective 1: Determine if the small RNA RyhB directly regulates RseA translation. This will be done by identifying nucleotide point mutaitons in the RyhB small RNA that affect its regulatory activity on PBAD-rseA27-lacZ.Next, an identification of compensatory nucleotide point mutations in the RseA 5'UTR portiion ofPBAD-rseA27-lacZtranslational fusion that restore the regulatory ability of RyhB point mutants.Objective 2: Determine if RyhB regulation of RseA affects σE Dependendent promoter activity in vivo.Objective 3: Determine if there is a link between iron metabolism and envelope stress.