5FRF

Solution structure of reduced and zinc-bound RsrA

Summary for 5FRF

• Entry DOI: 10.2210/pdb5frf/pdb
• NMR Information: BMRB: 25955
• Descriptor: ANTI-SIGMA FACTOR RSRA, ZINC ION (2 entities in total)
• Functional Keywords: transcription, anti-sigma factor, redox sensing
• Biological source: STREPTOMYCES COELICOLOR
• Total number of polymer chains: 1
• Total formula weight: 11900.47

Authors

Zdanowski, K.,Pecqueur, L.,Werner, J.,Potts, J.R.,Kleanthous, C. (deposition date: 2015-12-17, release date: 2016-08-03, Last modification date: 2024-05-15)

Primary citation

Rajasekar, K.V.,Zdanowski, K.,Yan, J.,Hopper, J.T.,Francis, M.L.,Seepersad, C.,Sharp, C.,Pecqueur, L.,Werner, J.M.,Robinson, C.V.,Mohammed, S.,Potts, J.R.,Kleanthous, C.
The Anti-Sigma Factor Rsra Responds to Oxidative Stress by Reburying its Hydrophobic Core.
Nat.Commun., 7:12194-, 2016

PubMed Abstract: Redox-regulated effector systems that counteract oxidative stress are essential for all forms of life. Here we uncover a new paradigm for sensing oxidative stress centred on the hydrophobic core of a sensor protein. RsrA is an archetypal zinc-binding anti-sigma factor that responds to disulfide stress in the cytoplasm of Actinobacteria. We show that RsrA utilizes its hydrophobic core to bind the sigma factor σ(R) preventing its association with RNA polymerase, and that zinc plays a central role in maintaining this high-affinity complex. Oxidation of RsrA is limited by the rate of zinc release, which weakens the RsrA-σ(R) complex by accelerating its dissociation. The subsequent trigger disulfide, formed between specific combinations of RsrA's three zinc-binding cysteines, precipitates structural collapse to a compact state where all σ(R)-binding residues are sequestered back into its hydrophobic core, releasing σ(R) to activate transcription of anti-oxidant genes.

PubMed: 27432510
DOI: 10.1038/NCOMMS12194

Experimental method

SOLUTION NMR