Publication Date:
1994-05-06
Description:
Carbon monoxide dehydrogenase catalyzes the synthesis of acetyl-coenzyme A from coenzyme A, a methyl group, and carbon monoxide. The carbon monoxide binds to a mixed metal center of the enzyme, which contains nickel bridged to an iron-sulfur cluster. Resonance Raman spectroscopy has been used to identify both C-O stretching and metal-CO stretching vibrations of the carbon monoxide adduct of the enzyme. This adduct was shown by isotopic exchange to be on the pathway for acetyl-coenzyme A synthesis. The metal to which carbon monoxide is bound was established to be iron, not nickel, by preparation of enzyme from bacteria grown on iron-54 and nickel-64. The Fe-CO frequency is low, 360 wave numbers, implying a weak bond, probably because of electron donation from sulfide and thiolate ligands of the iron. A bimetallic mechanism is proposed, in which carbon monoxide binds to an iron atom and is subsequently attacked by a methyl group on a nearby nickel atom, forming an acetyl ligand, which is then transferred to coenzyme A.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Qiu, D -- Kumar, M -- Ragsdale, S W -- Spiro, T G -- GM13498/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1994 May 6;264(5160):817-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Princeton University, NJ 08544.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8171334" target="_blank"〉PubMed〈/a〉
Keywords:
Acetyl Coenzyme A/metabolism
;
Aldehyde Oxidoreductases/*metabolism
;
Carbon Monoxide/*metabolism
;
Catalysis
;
Clostridium/enzymology
;
Coenzyme A/metabolism
;
Iron/*metabolism
;
Iron Isotopes
;
Isotopes
;
*Multienzyme Complexes
;
Nickel/*metabolism
;
Spectrum Analysis, Raman
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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