Hartmann Tobias, Schwanhold Nadine, Leimkühler Silke
Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, D-14476 Potsdam, Germany.
Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, D-14476 Potsdam, Germany.
Biochim Biophys Acta. 2015 Sep;1854(9):1090-100. doi: 10.1016/j.bbapap.2014.12.006. Epub 2014 Dec 13.
The global carbon cycle depends on the biological transformations of C1 compounds, which include the reductive incorporation of CO₂into organic molecules (e.g. in photosynthesis and other autotrophic pathways), in addition to the production of CO₂from formate, a reaction that is catalyzed by formate dehydrogenases (FDHs). FDHs catalyze, in general, the oxidation of formate to CO₂and H⁺. However, selected enzymes were identified to act as CO₂reductases, which are able to reduce CO₂to formate under physiological conditions. This reaction is of interest for the generation of formate as a convenient storage form of H₂for future applications. Cofactor-containing FDHs are found in anaerobic bacteria and archaea, in addition to facultative anaerobic or aerobic bacteria. These enzymes are highly diverse and employ different cofactors such as the molybdenum cofactor (Moco), FeS clusters and flavins, or cytochromes. Some enzymes include tungsten (W) in place of molybdenum (Mo) at the active site. For catalytic activity, a selenocysteine (SeCys) or cysteine (Cys) ligand at the Mo atom in the active site is essential for the reaction. This review will focus on the characterization of Mo- and W-containing FDHs from bacteria, their active site structure, subunit compositions and its proposed catalytic mechanism. We will give an overview on the different mechanisms of substrate conversion available so far, in addition to providing an outlook on bio-applications of FDHs. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
全球碳循环依赖于C1化合物的生物转化，其中包括将CO₂还原并入有机分子（如在光合作用和其他自养途径中），此外还包括由甲酸脱氢酶（FDHs）催化的从甲酸生成CO₂的反应。一般来说，FDHs催化甲酸氧化为CO₂和H⁺。然而，已鉴定出某些酶可作为CO₂还原酶，它们能够在生理条件下将CO₂还原为甲酸。该反应对于生成甲酸作为未来应用中H₂的便捷储存形式具有重要意义。除了兼性厌氧或需氧细菌外，在厌氧细菌和古细菌中也发现了含辅因子的FDHs。这些酶具有高度多样性，采用不同的辅因子，如钼辅因子（Moco）、铁硫簇和黄素，或细胞色素。一些酶在活性位点用钨（W）取代钼（Mo）。对于催化活性，活性位点中钼原子上的硒代半胱氨酸（SeCys）或半胱氨酸（Cys）配体对于该反应至关重要。本综述将重点关注细菌中含钼和含钨FDHs的特性、其活性位点结构、亚基组成及其提出的催化机制。除了展望FDHs的生物应用外，我们还将概述目前可用的不同底物转化机制。本文是名为：辅因子依赖性蛋白质：进化、化学多样性和生物应用的特刊的一部分。
