Structural and Mechanistic Insights into CO 2 Activation by Nitrogenase Iron Protein
Structural and Mechanistic Insights into CO 2 Activation by Nitrogenase Iron Protein
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固氮酶铁蛋白激活 CO 2 的结构和机制见解
DOI：
10.1002/chem.201903387
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Hu, Yilin
中科院分区：
文献类型：
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作者：
Rettberg, Lee A.;Stiebritz, Martin T.;Kang, Wonchull;Lee, Chi Chung;Ribbe, Markus W.;Hu, Yilin
当固氮酶的 Fe 蛋白簇以全铁 [Fe4S4]0 氧化态存在时，它会催化环境中 CO2 的还原。在这里，我们报告了一项结构和理论相结合的研究，探讨了全铁铁蛋白对二氧化碳的独特反应性。 [Fe4S4]0 和 [Fe4S4]+ 状态下的维氏固氮菌 Fe 蛋白的结构比较表明，高度保守的 Arg 对在 CO2 结合和还原中可能具有不对称功能。密度泛函理论 (DFT) 计算进一步支持了 O 通过“近端”Arg 的不对称配位以及 C 与全铁簇的独特 Fe 原子的结合，然后通过 Arg 的近端胍基团提供质子，最终导致 C−O 键断裂。这些结果为表面暴露、支架固定的 [Fe4S4] 簇的 CO2 活化提供了重要的机制和结构见解。
The Fe protein of nitrogenase catalyzes the ambient reduction of CO2when its cluster is present in the all‐ferrous, [Fe4S4]0oxidation state. Here, we report a combined structural and theoretical study that probes the unique reactivity of the all‐ferrous Fe protein toward CO2. Structural comparisons of theAzotobacter vinelandiiFe protein in the [Fe4S4]0and [Fe4S4]+states point to a possible asymmetric functionality of a highly conserved Arg pair in CO2binding and reduction. Density functional theory (DFT) calculations provide further support for the asymmetric coordination of O by the “proximal” Arg and binding of C to a unique Fe atom of the all‐ferrous cluster, followed by donation of protons by the proximate guanidinium group of Arg that eventually results in the scission of a C−O bond. These results provide important mechanistic and structural insights into CO2activation by a surface‐exposed, scaffold‐held [Fe4S4] cluster.