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Publication Abstract from PubMed

The mechanism of pI258 arsenate reductase (ArsC) catalyzed arsenate reduction, involving its P-loop structural motif and three redox active cysteines, has been unraveled. All essential intermediates are visualized with x-ray crystallography, and NMR is used to map dynamic regions in a key disulfide intermediate. Steady-state kinetics of ArsC mutants gives a view of the crucial residues for catalysis. ArsC combines a phosphatase-like nucleophilic displacement reaction with a unique intramolecular disulfide bond cascade. Within this cascade, the formation of a disulfide bond triggers a reversible "conformational switch" that transfers the oxidative equivalents to the surface of the protein, while releasing the reduced substrate.

All intermediates of the arsenate reductase mechanism, including an intramolecular dynamic disulfide cascade.,Messens J, Martins JC, Van Belle K, Brosens E, Desmyter A, De Gieter M, Wieruszeski JM, Willem R, Wyns L, Zegers I Proc Natl Acad Sci U S A. 2002 Jun 25;99(13):8506-11. Epub 2002 Jun 18. PMID:12072565^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.