[FeFe]-Hydrogenase Maturation: HydG-Catalyzed Synthesis of Carbon Monoxide
[FeFe]-Hydrogenase Maturation: HydG-Catalyzed Synthesis of Carbon Monoxide
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DOI：
10.1021/ja1012273
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发表时间：
2010-07-14
影响因子：
15
通讯作者：
Broderick, Joan B.
中科院分区：
文献类型：
--
作者：
Shepard, Eric M.;Duffus, Benjamin R.;Broderick, Joan B.
在[FeFe]-氢化酶的活性位点处的不寻常的有机金属H-簇的生物合成需要三个辅助蛋白，其中两个是自由基Ado Met酶（HydE，HydG），其中一个是GTdR（HydF）。我们在这里证明，HydG催化合成CO使用酪氨酸作为底物。通过使用脱氧血红蛋白作为报告者并监测碳氧血红蛋白的特征可见光谱特征的外观来检测CO产生。通过FTIR分析利用C-13-酪氨酸的测定以确认HbCO的产生并证明CO产物由酪氨酸合成。CO连接是[FeFe]，[NiFe]和[Fe]-唯一的氢化酶的活性位点的共同特征;然而，这是第一个报告的酶促合成CO的氢化酶成熟。
Biosynthesis of the unusual organometallic H-cluster at the active site of the [FeFe]-hydrogenase requires three accessory proteins, two of which are radical Ado Met 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 C-13-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.