Molecular Biology Commons^™

Sigma Factor N: A Novel Regulator Of Acid Resistance And Locus Of Enterocyte Effacement In Escherichia Coli O157:H7, Avishek Mitra

USF Tampa Graduate Theses and Dissertations

In enterohemorrhagic E. coli (EHEC) sigma factor N (σ^N) regulates glutamate-dependent acid resistance (GDAR) and the locus of enterocyte effacement (LEE), discrete genetic systems required for transmission and virulence of this intestinal pathogen. Regulation of these systems requires nitrogen regulatory protein C, NtrC, and is a consequence of NtrC/σ^N-dependent reduction in the activity of sigma factor S (σ^S). This study elucidates pathway components and stimuli for σ^N-directed regulation of GDAR and the LEE in EHEC. Deletion of fliZ, the product of which reduces σ^S activity, phenocopies rpoN (σ^N) …