1okg
3-mercaptopyruvate sulfurtransferase from Leishmania major
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedLeishmania major 3-mercaptopyruvate sulfurtransferase is a crescent-shaped molecule comprising three domains. The N-terminal and central domains are similar to the thiosulfate sulfurtransferase rhodanese and create the active site containing a persulfurated catalytic cysteine (Cys-253) and an inhibitory sulfite coordinated by Arg-74 and Arg-185. A serine protease-like triad, comprising Asp-61, His-75, and Ser-255, is near Cys-253 and represents a conserved feature that distinguishes 3-mercaptopyruvate sulfurtransferases from thiosulfate sulfurtransferases. During catalysis, Ser-255 may polarize the carbonyl group of 3-mercaptopyruvate to assist thiophilic attack, whereas Arg-74 and Arg-185 bind the carboxylate group. The enzyme hydrolyzes benzoyl-Arg-p-nitroanilide, an activity that is sensitive to the presence of the serine protease inhibitor N alpha-p-tosyl-L-lysine chloromethyl ketone, which also lowers 3-mercaptopyruvate sulfurtransferase activity, presumably by interference with the contribution of Ser-255. The L. major 3-mercaptopyruvate sulfurtransferase is unusual with an 80-amino acid C-terminal domain, bearing remarkable structural similarity to the FK506-binding protein class of peptidylprolyl cis/trans-isomerase. This domain may be involved in mediating protein folding and sulfurtransferase-protein interactions. The crystal structure of Leishmania major 3-mercaptopyruvate sulfurtransferase. A three-domain architecture with a serine protease-like triad at the active site.,Alphey MS, Williams RA, Mottram JC, Coombs GH, Hunter WN J Biol Chem. 2003 Nov 28;278(48):48219-27. Epub 2003 Sep 1. PMID:12952945[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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