PDBsum entry 5frh

Transcription

PDB id: 5frh

Contents

Protein chain

108 a.a.

PDB id:

5frh

Name:

Transcription

Title:

Solution structure of oxidised rsra

Structure:

Anti-sigma factor rsra. Chain: a. Synonym: regulator of sigr, sigma-r anti-sigma factor rsra. Engineered: yes. Mutation: yes

Source:

Streptomyces coelicolor. Organism_taxid: 1902. Expressed in: escherichia coli. Expression_system_taxid: 469008. Expression_system_variant: plyss

NMR struc:

10 models

Authors:

K.Zdanowski,L.Pecqueur,J.Werner,J.R.Potts,C.Kleanthous

Key ref:

K.V.Rajasekar et al. (2016). The anti-sigma factor RsrA responds to oxidative stress by reburying its hydrophobic core. Nat Commun, 7, 12194. PubMed id: 27432510 DOI: 10.1038/ncomms12194

Date:

17-Dec-15 Release date: 03-Aug-16

Protein chain

Q7AKG8  (RSRA_STRCO) -  Anti-sigma factor RsrA from Streptomyces coelicolor (strain ATCC BAA-471 / A3(2) / M145)

Seq: 105 a.a.

Struc: 108 a.a.*

* PDB and UniProt seqs differ at 5 residue positions (black crosses)

DOI no: 10.1038/ncomms12194

Nat Commun 7:12194 (2016)

PubMed id: 27432510

The anti-sigma factor RsrA responds to oxidative stress by reburying its hydrophobic core.

K.V.Rajasekar, K.Zdanowski, J.Yan, J.T.Hopper, M.L.Francis, C.Seepersad, C.Sharp, L.Pecqueur, J.M.Werner, C.V.Robinson, S.Mohammed, J.R.Potts, C.Kleanthous.

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.