[FeFe]-Hydrogenase Maturation: HydG-Catalyzed Synthesis of Carbon Monoxide
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- 作者：Eric M. Shepard ; Benjamin R. Duffus ; Simon J. George ; Shawn E. McGlynn ; Martin R. Challand ; Kevin D. Swanson ; Peter L. Roach ; Stephen P. Cramer ; John W. Peters ; Joan B. Broderick
- 刊名：Journal of the American Chemical Society
- 出版年：2010
- 出版时间：July 14, 2010
- 年：2010
- 卷：132
- 期：27
- 页码：9247-9249
- 全文大小：170K
- 年卷期：v.132,no.27(July 14, 2010)
- ISSN：1520-5126
文摘
Biosynthesis of the unusual organometallic H-cluster at the active site of the [FeFe]-hydrogenase requires three accessory proteins, two of which are radical AdoMet enzymes (HydE, HydG) and one of which is a GTPase (HydF). We demonstrate here that HydG catalyzes the synthesis of CO using tyrosine as a substrate. CO production was detected by using deoxyhemoglobin as a reporter and monitoring the appearance of the characteristic visible spectroscopic features of carboxyhemoglobin. Assays utilizing 13C-tyrosine were analyzed by FTIR to confirm the production of HbCO and to demonstrate that the CO product was synthesized from tyrosine. CO ligation is a common feature at the active sites of the [FeFe], [NiFe], and [Fe]-only hydrogenases; however, this is the first report of the enzymatic synthesis of CO in hydrogenase maturation.