A methylnickel intermediate in a bimetallic mechanism of acetyl-coenzyme A synthesis by anaerobic bacteria.
Resonance Raman (RR) spectroscopy was used to identify a methylnickel adduct (upsilon Ni-C = 422 wave numbers) of carbon monoxide dehydrogenase (CODH) from Clostridium thermoaceticum. Formed at a nickel/iron-sulfur cluster on CODH called center A, the methylnickel species is the precursor of the methyl group of acetyl-coenzyme A in an anaerobic pathway of carbon monoxide or carbon dioxide fixation. Rapid kinetic and RR studies demonstrated that methylation of nickel occurs by heterolysis of the methyl-cobalt bond (upsilon Co-C = 429 wave numbers) of a methylated corrinoid/iron-sulfur protein. In combination with the earlier finding of an iron-carbonyl adduct at center A, detection of the methylnickel intermediate establishes a bimetallic mechanism for acetyl-coenzyme A synthesis.
Kumar
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M
Department of Biochemistry, Beadle Center, University of Nebraska, Lincoln 68588-0664, USA.
Qiu
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D
Spiro
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TG
Ragsdale
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D000105:Acetyl Coenzyme A / Q000096:biosynthesis*; D000445:Aldehyde Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D000693:Anaerobiosis; D002244:Carbon / Q000737:chemistry / Q000378:metabolism; D002248:Carbon Monoxide / Q000378:metabolism; D003013:Clostridium / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism*; D008667:Metalloproteins / Q000737:chemistry / Q000378:metabolism*; D008745:Methylation; D009097:Multienzyme Complexes; D009532:Nickel / Q000378:metabolism*; D013059:Spectrum Analysis, Raman
D007506:Iron-Sulfur Proteins; D008667:Metalloproteins; D009097:Multienzyme Complexes; D000105:Acetyl Coenzyme A; D002244:Carbon; D009532:Nickel; D002248:Carbon Monoxide; D007501:Iron; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase