title: FRET-based system for probing protein-protein interactions between σR and RsrA from Streptomyces coelicolor in response to the redox environment.
abstract: Protein-protein interactions between sigma factor σ(R) and its corresponding zinc-binding anti-sigma (ZAS) protein RsrA trigger the thioredoxin system for maintaining cellular redox homeostasis in S. coelicolor. RsrA bound to zinc associates with σ(R), inhibiting its transcriptional activity in a reducing environment. During disulfide stress it forms intramolecular disulfide bonds, leading to zinc release and dissociation from σ(R), which initiates transcription to produce reductase and thioredoxin. We designed a fluorescence resonance energy transfer (FRET) based system for monitoring protein-protein interactions between σ(R) and RsrA to further understand how this redox switch regulates the thioredoxin system in S. coelicolor in response to its redox environment, especially various reactive oxygen species (ROS) derived from different metabolic pathways, and clarify the different response mechanisms between Zn-RsrA and apo-RsrA. By the use of the FRET approach described here, we showed that zinc protected thiols in RsrA and causes the σ(R)-RsrA complex to form a more compact structure. This system was also utilized to detect changes in redox status induced by ROS and diamide in real time in E. coli cells.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Zi-Han
authors.initials: ZH
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Bang-Ce
authors.initials: BC
authors.lastname: Ye
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D015374:Biosensing Techniques; D002942:Circular Dichroism; D031541:Fluorescence Resonance Energy Transfer; D007368:Interferometry; D015335:Molecular Probes / Q000378:metabolism; D010084:Oxidation-Reduction; D011485:Protein Binding; D025941:Protein Interaction Mapping; D017382:Reactive Oxygen Species / Q000378:metabolism; D015203:Reproducibility of Results; D048372:Streptomyces coelicolor / Q000378:metabolism*; D013816:Thermodynamics; D014157:Transcription Factors / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D015335:Molecular Probes; D017382:Reactive Oxygen Species; C121147:RsrA protein, Streptomyces coelicolor; D014157:Transcription Factors; D015032:Zinc