PDBsum entry 1z2e

Oxidoreductase

PDB id: 1z2e

Contents

Protein chain

139 a.a. *

* Residue conservation analysis

PDB id:

1z2e

Name:

Oxidoreductase

Title:

Solution structure of bacillus subtilis arsc in oxidized state

Structure:

Arsenate reductase. Chain: a. Synonym: arsenical pump modifier. Engineered: yes

Source:

Bacillus subtilis. Organism_taxid: 1423. Expressed in: escherichia coli. Expression_system_taxid: 562

NMR struc:

20 models

Authors:

C.Jin,Y.Li

Key ref:

X.Guo et al. (2005). Solution structures and backbone dynamics of arsenate reductase from Bacillus subtilis: reversible conformational switch associated with arsenate reduction. J Biol Chem, 280, 39601-39608. PubMed id: 16192272 DOI: 10.1074/jbc.M508132200

Date:

08-Mar-05 Release date: 04-Oct-05

Protein chain

P45947  (ARSC_BACSU) -  Arsenate reductase from Bacillus subtilis (strain 168)

Seq: 139 a.a.

Struc: 139 a.a.

Enzyme reactions

• Enzyme class: E.C.1.20.4.4 - arsenate reductase (thioredoxin).
• Reaction: arsenate + [thioredoxin]-dithiol + H⁺ = arsenite + [thioredoxin]- disulfide + H2O

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1074/jbc.M508132200

J Biol Chem 280:39601-39608 (2005)

PubMed id: 16192272

Solution structures and backbone dynamics of arsenate reductase from Bacillus subtilis: reversible conformational switch associated with arsenate reduction.

X.Guo, Y.Li, K.Peng, Y.Hu, C.Li, B.Xia, C.Jin.

ABSTRACT

Arsenate reductase encoded by the chromosomal arsC gene in Bacillus subtilis catalyzes the intracellular reduction of arsenate to arsenite, which is then extruded from cells through an efficient and specific transport system. Herein, we present the solution structures and backbone dynamics of both the reduced and oxidized forms of arsenate reductase from B. subtilis. The overall structures of both forms are similar to those of bovine low molecular weight protein-tyrosine phosphatase and arsenate reductase from Staphylococcus aureus. However, several features of the tertiary structure and mobility are notably different between the reduced and oxidized forms of B. subtilis arsenate reductase, particularly in the P-loop region and the segment Cys(82)-Cys(89). The backbone dynamics results demonstrated that the reduced form of arsenate reductase undergoes millisecond conformational changes in the functional P-loop and Cys(82)-Cys(89), which may facilitate the formation of covalent intermediates and subsequent reduction of arsenate. In the oxidized form, Cys(82)-Cys(89) shows motional flexibility on both picosecond-to-nanosecond and possibly millisecond time scales, which may facilitate the reduction of the oxidized enzyme by thioredoxin to regenerate the active enzyme. Overall, the internal dynamics and static structures of the enzyme provide insights into the molecular mechanism of arsenate reduction, especially the reversible conformational switch and changes in internal motions associated with the catalytic reaction.

Selected figure(s)

Figure 3.
FIGURE 3. Structural comparison. A, overlay of the C^ trace of the solution structures of the reduced (red) and oxidized (green) forms of B. subtilis ArsC; B, comparison of the local structures of the P-loop of the reduced (left) and oxidized (right) forms of ArsC; C, the C^ trace of reduced B. subtilis ArsC in solution (red) superimposed with chain A of the crystal structure (blue); D, the C^ trace of reduced B. subtilis ArsC (red) superimposed with that of bovine low molecular weight protein-tyrosine phosphatase (magenta); E, the C^ trace of reduced B. subtilis ArsC (red) superimposed with that of S. aureus ArsC (cyan); F, the C^ trace of oxidized B. subtilis ArsC (green) superimposed with that of S. aureus ArsC (yellow).

Figure 5.
FIGURE 5. Ribbon diagrams representing the dynamic properties of B. subtilis ArsC. The ribbon diagrams of the reduced (A) and oxidized (B) forms of B. subtilis ArsC represent the internal motions on picosecond-to-nanosecond time scales, with colors ranging from yellow to red and magenta corresponding to [e] values from 10 to 100 ps and >100 ps, respectively. The ribbon diagrams of the reduced (C) and oxidized (D) forms of B. subtilis ArsC represent the residues with conformational changes (R[ex] > 1 s-1) on the millisecond time scale, colored in blue.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2005, 280, 39601-39608) copyright 2005.

Figures were selected by an automated process.