2PEX

Structure of reduced C22S OhrR from Xanthamonas Campestris

Summary for 2PEX

• Entry DOI: 10.2210/pdb2pex/pdb
• Related: 1Z91 1Z9C 2PFB
• Descriptor: Transcriptional regulator OhrR, FORMIC ACID (3 entities in total)
• Functional Keywords: transcription regulator
• Biological source: Xanthomonas campestris
• Total number of polymer chains: 2
• Total formula weight: 34199.05

Authors

Brennan, R.G.,Newberry, K.J. (deposition date: 2007-04-03, release date: 2007-12-11, Last modification date: 2024-02-21)

Primary citation

Newberry, K.J.,Fuangthong, M.,Panmanee, W.,Mongkolsuk, S.,Brennan, R.G.
Structural Mechanism of Organic Hydroperoxide Induction of the Transcription Regulator OhrR.
Mol.Cell, 28:652-664, 2007

PubMed Abstract: The Xanthomonas campestris transcription regulator OhrR contains a reactive cysteine residue (C22) that upon oxidation by organic hydroperoxides (OHPs) forms an intersubunit disulphide bond with residue C127'. Such modification induces the expression of a peroxidase that reduces OHPs to their less toxic alcohols. Here, we describe the structures of reduced and OHP-oxidized OhrR, visualizing the structural mechanism of OHP induction. Reduced OhrR takes a canonical MarR family fold with C22 and C127' separated by 15.5 A. OHP oxidation results in the disruption of the Y36'-C22-Y47' interaction network and dissection of helix alpha5, which then allows the 135 degrees rotation and 8.2 A translation of C127', formation of the C22-C127' disulphide bond, and alpha6-alpha6' helix-swapped reconfiguration of the dimer interface. These changes result in the 28 degrees rigid body rotations of each winged helix-turn-helix motif and DNA dissociation. Similar effector-induced rigid body rotations are expected for most MarR family members.

PubMed: 18042459
DOI: 10.1016/j.molcel.2007.09.016

Experimental method

X-RAY DIFFRACTION (1.9 Å)