PDBsum entry 1i6a

Transcription

PDB id: 1i6a

Contents

Protein chain

212 a.a. *

Waters ×59

* Residue conservation analysis

References listed in PDB file

Key reference

Title

Structural basis of the redox switch in the oxyr transcription factor.

Authors

H.Choi, S.Kim, P.Mukhopadhyay, S.Cho, J.Woo, G.Storz, S.Ryu.

Ref.

Cell, 2001, 105, 103-113. [DOI no: 10.1016/S0092-8674(01)00300-2]

PubMed id

11301006

Abstract

The Escherichia coli OxyR transcription factor senses H2O2 and is activated through the formation of an intramolecular disulfide bond. Here we present the crystal structures of the regulatory domain of OxyR in its reduced and oxidized forms, determined at 2.7 A and 2.3 A resolutions, respectively. In the reduced form, the two redox-active cysteines are separated by approximately 17 A. Disulfide bond formation in the oxidized form results in a significant structural change in the regulatory domain. The structural remodeling, which leads to different oligomeric associations, accounts for the redox-dependent switch in OxyR and provides a novel example of protein regulation by "fold editing" through a reversible disulfide bond formation within a folded domain.

Figure 2.
Figure 2. Structural Transition within MonomerThe environment of the redox-active cysteines in the reduced (A) and oxidized (B) forms of OxyR. The redox-active cysteines Cys-199 (Ser-199 in the reduced form) and Cys-208, and the neighboring residues, are shown in a ball-and-stick representation on a ribbon diagram of the region. The point of view is approximately from the left side of the monomers presented in Figure 1

Figure 3.
Figure 3. Electron Density Maps of the Redox-Active Cysteine RegionThe 2Fo−Fc maps of the reduced (A) and oxidized (B) forms are superposed with the refined models. The maps are contoured at a 0.9 σ level

The above figures are reprinted by permission from Cell Press: Cell (2001, 105, 103-113) copyright 2001.