Publication Date:
1998-12-04
Description:
A three-dimensional structure for the monomeric iron-containing hydrogenase (CpI) from Clostridium pasteurianum was determined to 1.8 angstrom resolution by x-ray crystallography using multiwavelength anomalous dispersion (MAD) phasing. CpI, 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Peters, J W -- Lanzilotta, W N -- Lemon, B J -- Seefeldt, L C -- New York, N.Y. -- Science. 1998 Dec 4;282(5395):1853-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA. petersj@cc.usu.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9836629" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Binding Sites
;
Carbon Monoxide/chemistry
;
Catalytic Domain
;
Clostridium/*enzymology
;
Crystallography, X-Ray
;
Cyanides/chemistry
;
Cysteine/chemistry
;
Histidine/chemistry
;
Hydrogen/metabolism
;
Hydrogenase/*chemistry/metabolism
;
Iron/*chemistry
;
Ligands
;
Models, Molecular
;
Molecular Sequence Data
;
Oxidation-Reduction
;
*Protein Conformation
;
Protein Folding
;
Protein Structure, Secondary
;
Protons
;
Sulfur/chemistry
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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