Regulation of nrf operon expression in pathogenic enteric bacteria: sequence divergence reveals new regulatory complexity.

ABSTRACT: The Escherichia coli K-12 nrf operon encodes a periplasmic nitrite reductase, the expression of which is driven from a single promoter, pnrf. Expression from pnrf is activated by the FNR transcription factor in response to anaerobiosis and further increased in response to nitrite by the response regulator proteins, NarL and NarP. FNR-dependent transcription is suppressed by the binding of two nucleoid associated proteins, IHF and Fis. As Fis levels increase in cells grown in rich medium, the positioning of its binding site, overlapping the promoter -10 element, ensures that pnrf is sharply repressed. Here, we investigate the expression of the nrf operon promoter from various pathogenic enteric bacteria. We show that pnrf from enterohaemorrhagic E. coli is more active than its K-12 counterp

SUBMITTER: Godfrey RE 

PROVIDER: S-EPMC5434802 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature