Species-specific residues calibrate SoxR sensitivity to redox-active molecules.

ABSTRACT: In enterics, the transcription factor SoxR triggers a global stress response by sensing a broad spectrum of redox-cycling compounds. In the non-enteric bacteria Pseudomonas aeruginosa and Streptomyces coelicolor, SoxR is activated by endogenous redox-active small molecules and only regulates a small set of genes. We investigated if the more general response in enterics is reflected in the ability of SoxR to sense a wider range of redox-cycling compounds. Indeed, while Escherichia coli SoxR is tuned to structurally diverse compounds that span a redox range of -450 to +80 mV, P. aeruginosa and S. coelicolor SoxR are less sensitive to viologens, which have redox potentials below -350 mV. Using a mutagenic approach, we pinpointed three amino acids that contribute to the reduced sensitivity of

SUBMITTER: Sheplock R 

PROVIDER: S-EPMC3545107 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature