Nature carefully selects specific metal ions for incorporation into the enzymes that catalyse the chemical reactions necessary for life. Hydrogenases, enzymes that activate molecular H2, exclusively utilize Ni and Fe in [NiFe]-, [FeFe]- and [Fe]-hydrogeanses. However, other transition metals are known to activate or catalyse the production of hydrogen in synthetic systems. Here, we report the development of a biomimetic model complex of [Fe]-hydrogenase that incorporates a Mn, as opposed to a Fe, metal centre. This Mn complex is able to heterolytically cleave H2 as well as catalyse hydrogenation reactions. The incorporation of the model into an apoenzyme of [Fe]-hydrogenase results in a [Mn]-hydrogenase with an enhanced occupancy-normalized activity over an analogous semi-synthetic [Fe]-hydrogenase. These findings demonstrate a non-native metal hydrogenase that shows catalytic functionality and that hydrogenases based on a manganese active site are viable.

中文翻译：

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一种具有催化活性的 [Mn]-氢化酶，掺入非天然金属辅因子。

大自然精心选择特定的金属离子，以掺入催化生命所必需的化学反应的酶中。氢化酶是激活分子 H2 的酶，专门在 [NiFe]-、[FeFe]- 和 [Fe]-水凝胶中利用 Ni 和 Fe。然而，已知其他过渡金属可以在合成体系中激活或催化氢气的产生。在这里，我们报告了 [Fe]-氢化酶的仿生模型复合物的开发，该复合物包含 Mn，而不是 Fe 金属中心。这种 Mn 配合物能够异溶裂解 H2 并催化氢化反应。将模型掺入 [Fe]-氢化酶的脱辅基酶中，产生 [Mn]-氢化酶，与类似的半合成 [Fe]-氢化酶相比，其占位归一化活性增强。这些发现证明了一种非天然金属氢化酶，它显示出催化功能，并且基于锰活性位点的氢化酶是可行的。