Journal Article

X-ray crystal structure of the Fe-only hydrogenase (Cpl) from Clostridium pasteurianum to 1.8 angstrom resolution

Lanzilotta, W.N, Seefeldt, L.C, Peters, J.W. (Utah State University, Logan, UT.), Lemon, B.J

1998

Overview

A three-dimensional structure for the monomeric iron-containing hydrogenase (Cpl) from Clostridium pasteurianum was determined to 1.8 angstrom resolution by X-ray crystallography using multiwavelength anomalous dispersion (MAD) phasing. Cpl, an enzyme that catalyzes the two-electron reduction of two protons to yield dihydrogen, was found to contain 20 gram atoms of iron per mole of protein, arranged into five distinct [Fe-S] clusters. The probable active-site cluster, previously termed the H-cluster, was found to be an unexpected arrangement of six iron atoms existing as a [4Fe-4S] cubane subcluster covalently bridged by a cysteinate thiol to a [2Fe] subcluster. The iron atoms of the [2Fe] subcluster both exist with an octahedral coordination geometry and are bridged to each other by three non-protein atoms, assigned as two sulfide atoms and one carbonyl or cyanide molecule. This structure provides insights into the mechanism of biological hydrogen activation and has broader implications for [Fe-S] cluster structure and function in biological systems

• Publisher: American Society for the Advancement of Science,American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Active sites / Amino Acid Sequence / Analytical, structural and metabolic biochemistry / Atoms / Bacteria / Binding Sites / Biochemistry / Biohydrogen / Biological and medical sciences / Carbon Monoxide - chemistry / Carbonyl compounds / Catalytic Domain / Clostridium - enzymology / CLOSTRIDIUM PASTEURIANUM / Crystallography / Crystallography, X-Ray / Crystals / Cyanides - chemistry / Cysteine - chemistry / Electron density / Electrons / Enzymes / Enzymes and enzyme inhibitors / ferredoxin hydrogenase / Fundamental and applied biological sciences. Psychology / Histidine - chemistry / Hydrogen / Hydrogen - metabolism / Hydrogenase - chemistry / Hydrogenase - metabolism / Inhalants / Iron / Iron - chemistry / Ligands / Models, Molecular / Molecular Sequence Data / Molecules / Oxidation-Reduction / OXIDOREDUCTASES / OXIDORREDUCTASAS / OXYDOREDUCTASE / Protein Conformation / Protein Folding / Protein Structure, Secondary / Protons / Sulfur - chemistry / X RAY CRYSTALLOGRAPHY / X-ray diffraction / X-rays