Fine-Tuning Modulation of Oxidation-Mediated Posttranslational Control of Bradyrhizobium diazoefficiens FixK₂ Transcription Factor.

ABSTRACT: FixK₂ is a CRP/FNR-type transcription factor that plays a central role in a sophisticated regulatory network for the anoxic, microoxic and symbiotic lifestyles of the soybean endosymbiont Bradyrhizobium diazoefficiens. Aside from the balanced expression of the fixK₂ gene under microoxic conditions (induced by the two-component regulatory system FixLJ and negatively auto-repressed), FixK₂ activity is posttranslationally controlled by proteolysis, and by the oxidation of a singular cysteine residue (C183) near its DNA-binding domain. To simulate the permanent oxidation of FixK₂, we replaced C183 for aspartic acid. Purified C183D FixK₂ protein showed both low DNA binding and in vitro transcriptional activation from the promo

SUBMITTER: Parejo S 

PROVIDER: S-EPMC9104804 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature