title: Reconstitution of [Fe]-hydrogenase using model complexes.
abstract: [Fe]-Hydrogenase catalyses the reversible hydrogenation of a methenyltetrahydromethanopterin substrate, which is an intermediate step during the methanogenesis from CO2 and H2. The active site contains an iron-guanylylpyridinol cofactor, in which Fe(2+) is coordinated by two CO ligands, as well as an acyl carbon atom and a pyridinyl nitrogen atom from a 3,4,5,6-substituted 2-pyridinol ligand. However, the mechanism of H2 activation by [Fe]-hydrogenase is unclear. Here we report the reconstitution of [Fe]-hydrogenase from an apoenzyme using two FeGP cofactor mimics to create semisynthetic enzymes. The small-molecule mimics reproduce the ligand environment of the active site, but are inactive towards H2 binding and activation on their own. We show that reconstituting the enzyme using a mimic that contains a 2-hydroxypyridine group restores activity, whereas an analogous enzyme with a 2-methoxypyridine complex was essentially inactive. These findings, together with density functional theory computations, support a mechanism in which the 2-hydroxy group is deprotonated before it serves as an internal base for heterolytic H2 cleavage.
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Marburg 35043, Germany.|PRESTO, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Shima
authors.affiliation: School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Dafa
authors.initials: D
authors.lastname: Chen
authors.affiliation: Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Science and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.affiliation: Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Science and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.|Laboratory for Computational Molecular Design, Institute of Chemical Science and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Wodrich
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Marburg 35043, Germany.
authors.forename: Takashi
authors.identifier: http://orcid.org/0000-0001-7967-8380
authors.initials: T
authors.lastname: Fujishiro
authors.affiliation: Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Science and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Schultz
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Marburg 35043, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Kahnt
authors.affiliation: Department of Physics, Freie Universität Berlin, Berlin 14195, Germany.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ataka
authors.affiliation: Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Science and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
authors.forename: Xile
authors.initials: X
authors.lastname: Hu
mesh_terms: D020134:Catalytic Domain; D003067:Coenzymes / Q000737:chemistry* / Q000378:metabolism; D006859:Hydrogen / Q000737:chemistry / Q000378:metabolism; D006864:Hydrogenase / Q000737:chemistry* / Q000378:metabolism*; D006865:Hydrogenation; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D015394:Molecular Structure; D011622:Pterins / Q000737:chemistry* / Q000378:metabolism; D011725:Pyridines / Q000737:chemistry* / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D003067:Coenzymes; D007506:Iron-Sulfur Proteins; D011622:Pterins; D011725:Pyridines; C544442:methenyltetrahydromethanopterin; D006859:Hydrogen; C118830:iron hydrogenase; D006864:Hydrogenase