PMID: 17469833

Authors:

Di Costanzo L, Pique ME, Christianson DW

Title:

Crystal structure of human arginase I complexed with thiosemicarbazide reveals an unusual thiocarbonyl mu-sulfide ligand in the binuclear manganese cluster.

Journal:

J Am Chem Soc. 2007 May 23;129(20):6388-9. doi: 10.1021/ja071567j. Epub 2007 May , 1.

Abstract:

The crystal structure of the human arginase I-thiosemicarbazide complex reveals an unusual thiocarbonyl mu-sulfide ligand in the binuclear manganese cluster. The C=S moiety of thiosemicarbazide bridges Mn(2+)A and Mn(2+)B with coordination distances of 2.6 A and 2.4 A, respectively. Otherwise, the binding of thiosemicarbazide to human arginase I does not cause any significant structural changes in the active site. The crystal structure of the unliganded enzyme reveals a hydrogen bonded water molecule that could support proton transfer between a mu-water molecule and H141 to regenerate the nucleophilic mu-hydroxide ion in the final step of catalysis.