|Title||The structure of a triple mutant of pI258 arsenate reductase from Staphylococcus aureus and its 5-thio-2-nitrobenzoic acid adduct.|
|Publication Type||Journal Article|
|Year of Publication||2004|
|Authors||Messens, J., I. Van Molle, P. Vanhaesebrouck, K. Van Belle, K. Wahni, J. C. Martins, L. Wyns, and R. Loris|
|Journal||Acta Crystallogr D Biol Crystallogr|
|Date Published||2004 Jun|
|Keywords||Arsenite Transporting ATPases, Crystallography, X-Ray, Dimerization, Disulfides, Electrons, Electrophoresis, Polyacrylamide Gel, Escherichia coli, Histidine, Ion Pumps, Mass Spectrometry, Models, Molecular, Multienzyme Complexes, Mutagenesis, Site-Directed, Mutation, Nitrobenzoates, Oxidation-Reduction, Protein Conformation, Protein Folding, Protein Structure, Secondary, Protein Structure, Tertiary, Staphylococcus aureus, Sulfhydryl Compounds|
Structural insights into formation of the complex between the ubiquitous thiol-disulfide oxidoreductase thioredoxin and its oxidized substrate are under-documented owing to its entropical instability. In vitro, it is possible via a reaction with 5,5'-dithiobis-(2-nitrobenzoic acid) to make a stable mixed-disulfide complex between thioredoxin from Staphylococcus aureus and one of its substrates, oxidized pI258 arsenate reductase (ArsC) from S. aureus. In the absence of the crystal structure of an ArsC-thioredoxin complex, the structures of two precursors of the complex, the ArsC triple mutant ArsC C10SC15AC82S and its 5-thio-2-nitrobenzoic acid (TNB) adduct, were determined. The ArsC triple mutant has a structure very similar to that of the reduced form of wild-type ArsC, with a folded redox helix and a buried catalytic Cys89. In the adduct form, the TNB molecule is buried in a hydrophobic pocket and the disulfide bridge between TNB and Cys89 is sterically inaccessible to thioredoxin. In order to form a mixed disulfide between ArsC and thioredoxin, a change in the orientation of the TNB-Cys89 disulfide in the structure is necessary.
|Alternate Journal||Acta Crystallogr. D Biol. Crystallogr.|
The structure of a triple mutant of pI258 arsenate reductase from Staphylococcus aureus and its 5-thio-2-nitrobenzoic acid adduct.