Purification and Biochemical Characterization of the DNA Binding Domain of the Nitrogenase Transcriptional Activator NifA from Gluconacetobacter diazotrophicus.

ABSTRACT: NifA is a σ⁵⁴ activator that turns on bacterial nitrogen fixation under reducing conditions and when fixed cellular nitrogen levels are low. The redox sensing mechanism in NifA is poorly understood. In α- and β-proteobacteria, redox sensing involves two pairs of Cys residues within and immediately following the protein's central AAA⁺ domain. In this work, we examine if an additional Cys pair that is part of a C(X)₅ C motif and located immediately upstream of the DNA binding domain of NifA from the α-proteobacterium Gluconacetobacter diazotrophicus (Gd) is involved in redox sensing. We hypothesize that the Cys residues' redox state may directly influence the DNA binding domain's DNA binding affinity and/or alter the protein's oligomeric sate. Two DNA binding

SUBMITTER: Standke HG 

PROVIDER: S-EPMC10590331 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature