X-ray Absorption Spectroscopic Characterization of the Molybdenum Site of Escherichia coli Dimethyl Sulfoxide Reductase

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• 作者：Graham N. George ; Christian J. Doonan ; Richard A. Rothery ; Nasim Boroumand ; Joel H. Weiner
• 刊名：Inorganic Chemistry
• 出版年：2007
• 出版时间：January 8, 2007
• 年：2007
• 卷：46
• 期：1
• 页码：2 - 4
• 全文大小：47K
• 年卷期：v.46,no.1(January 8, 2007)
• ISSN：1520-510X

文摘

Structural studies of dimethyl sulfoxide (DMSO) reductases werehampered by modification of the active site during purification. Wereport an X-ray absorption spectroscopic analysis of the molybdenum active site of Escherichia coli DMSO reductase containedwithin its native membranes. The enzyme in these preparations isexpected to be very close to the form found in vivo. The oxidizedactive site was found to have four Mo-S ligands at 2.43 Å, oneMo=O at 1.71 Å, and a longer Mo-O at 1.90 Å. We concludethat the oxidized enzyme is a monooxomolybdenum(VI) speciescoordinated by two molybdopterin dithiolenes and a serine. Thebond lengths determined for E. coli DMSO reductase are verysimilar to those determined for the well-characterized Rhodobactersphaeroides DMSO reductase, suggesting similar active sitestructures for the two enzymes. Furthermore, our results suggestthat the form found in vivo is the monooxobis(molybdopterin)species.