Carbon dioxide activation at the Ni,Fe-cluster of anaerobic carbon monoxide dehydrogenase
Carbon dioxide activation at the Ni,Fe-cluster of anaerobic carbon monoxide dehydrogenase
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DOI：
10.1126/science.1148481
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发表时间：
2007-11-30
期刊：
影响因子：
56.9
通讯作者：
Dobbek, Holger
中科院分区：
文献类型：
--
作者：
Jeoung, Jae-Hun;Dobbek, Holger
厌氧CO脱氢酶催化CO在复杂的含Ni-、Fe-和S的金属中心（称为簇C）处可逆氧化为CO2。我们报告了来自产氢碳热菌的CO脱氢酶II在三种不同状态下的晶体结构。在还原状态下，溶液中提供的外源CO2被簇C结合并还原活化。在中间结构中，CO2作为Ni和不对称配位Fe之间的桥接配体，在那里它完成了Ni离子的正方形平面配位。它取代了水/羟基配体结合到铁离子在其他两个国家。这些结构确定了C原子簇Ni-Fe位CO氧化和CO2还原的机理。
Anaerobic CO dehydrogenases catalyze the reversible oxidation of CO to CO2 at a complex Ni-, Fe-, and S-containing metal center called cluster C. We report crystal structures of CO dehydrogenase II from Carboxydothermus hydrogenoformans in three different states. In a reduced state, exogenous CO2 supplied in solution is bound and reductively activated by cluster C. In the intermediate structure, CO2 acts as a bridging ligand between Ni and the asymmetrically coordinated Fe, where it completes the square-planar coordination of the Ni ion. It replaces a water/hydroxo ligand bound to the Fe ion in the other two states. The structures define the mechanism of CO oxidation and CO2 reduction at the Ni-Fe site of cluster C.