Conformational changes in the novel redox sensor protein HbpS studied by site-directed spin labeling and its turnover in dependence on the catalase-peroxidase CpeB.

ABSTRACT:

Aims

To establish conditions to study the oligomeric assembly of heme-binding protein (HbpS) in solution by applying the tools of site-directed spin labeling combined with pulse electron paramagnetic resonance (SDSL EPR) spectroscopy, as well as to analyze redox stress-based conformational changes in HbpS subunits within the oligomer in solution. In vivo elucidation of molecular mechanisms that control the downregulation of the novel redox-system HbpS-SenS-SenR.

Results

Using a set of specifically generated HbpS mutants, and SDSL EPR spectroscopy, we show the octomeric assembly of HbpS in solution, and demonstrate that iron-mediated stress induces conformational changes in HbpS subunits within the octamer. We further demonstrate that the catalase-peroxidase CpeB protects Hbp

SUBMITTER: Klare JP 

PROVIDER: S-EPMC3277929 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature