title: Revealing the absolute configuration of the CO and CN- ligands at the active site of a [NiFe] hydrogenase.
abstract: Combined molecular dynamics (MD) and quantum mechanical/molecular mechanical (QM/MM) calculations were performed on the crystal structure of the reduced membrane-bound [NiFe] hydrogenase (MBH) from Ralstonia eutropha to determine the absolute configuration of the CO and the two CN(-)  ligands bound to the active-site iron of the enzyme. For three models that include the CO ligand at different positions, often indistinguishable on the basis of the crystallographic data, we optimized the structures and calculated the ligand stretching frequencies. Comparison with the experimental IR data reveals that the CO ligand is in trans position to the substrate-binding site of the bimetallic [NiFe] cluster.
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Berlin, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Rippers
authors.forename: Marius
authors.initials: M
authors.lastname: Horch
authors.forename: Peter
authors.initials: P
authors.lastname: Hildebrandt
authors.forename: Ingo
authors.initials: I
authors.lastname: Zebger
authors.forename: Maria Andrea
authors.initials: MA
authors.lastname: Mroginski
mesh_terms: D002248:Carbon Monoxide / Q000737:chemistry*; D020134:Catalytic Domain; D003461:Crystallography / Q000379:methods; D020118:Cupriavidus necator / Q000378:metabolism; D003486:Cyanides / Q000737:chemistry*; D006864:Hydrogenase / Q000737:chemistry* / Q000378:metabolism*; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D056004:Molecular Dynamics Simulation; D009532:Nickel / Q000737:chemistry / Q000378:metabolism; D011789:Quantum Theory
chemical_list: D003486:Cyanides; D008024:Ligands; D009532:Nickel; D002248:Carbon Monoxide; D007501:Iron; C043296:nickel-iron hydrogenase; D006864:Hydrogenase