Mononuclear molybdenum enzyme

The enzymes that utilize molybdenum can be grouped into two broad categories (1) the nitrogenases, where Mo is part of a multinu-clear metal center, or (2) the mononuclear molybdenum enzymes, such as xanthine oxidase (XO), dimethyl sulfoxide (DMSO) reductase, formate dehydrogenase (FDH), and sulfite oxidase (SO). The last... 

Helz GR, Miller CV, Chamock JM, Mosselmans JEW, Pattrick RAD, Gamer CD, Vaughn DJ (1996) Mechanism of molybdenum removal from the sea and its concentration in black shales EXAFS evidence. Geochim Cosmochim Acta 60 3631-3642 Hille R (1996) The mononuclear molybdenum enzymes. Chem Rev 96 2757-2816... 

The nomenclature used by scientists working in the mononuclear molybdenum enzyme field has been a cause of confusion and contention (1, 59). For many years, the molybdenum atom and its ligands at the catalytic site has been referred to as the molybdenum cofactor and Moco or Mo-co (1, 60, 61). 

Hille, R., 1996, The mononuclear molybdenum enzymes, Chem. Rev. 96 2757n2816. 

DMSO) reductase and biotin-S-oxidoreduc-tase, as well as the bacterial dissimilatory (or respiratory) nitrate reductases (Hille 1996) (Table 18.8). The mononuclear molybdenum enzymes possess a pterin cofactor and may be categorized based on the structure of their molybdenum center... 

The sulphite oxidase family Fig. 18.2 The major families of mononuclear molybdenum enzymes (Hille 1996). 

Arr contains molybdenum, iron, and acid-labile sulfur (14). It appears to be a member of the family of mononuclear molybdenum enzymes (16). Approximately 14 0.4 mol equivalents of iron and 16.4 0.8 mol equivalents of acid-labile sulfur are present, suggesting that Arr contains several iron-sulfur clusters as prosthetic groups. 

Aro contains molybdenum and preliminary data suggest the presence of iron. Further analyses, however, are required to confirm the presence of iron and determine whether acid-labile sulfur is also present in the enzyme. The Aro therefore appears to be a member of mononuclear molybdenum enzymes (15). In addition, the N-terminal sequence of the large subunit (AroA) has sequence similarities with molybdenum-containing subunits of a number of enzymes (Fig. 

R Hille. The mononuclear molybdenum enzymes. Chem Rev 96 2757-2816 1996. NA Turner, RC Bray, GP Diakun. Information from E.X.A.F.S. spectroscopy on the structures of different forms of molybdenum in xanthine oxidase and the catalytic mechanism of the enzyme. Biochem J 260 563, 1989. 

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