This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hu, S I Articles by Wood, H G Search for Related Content PubMed PubMed Citation Articles by Hu, S I Articles by Wood, H G

 Previous Article  |  Next Article 

J Bacteriol. 1982 February; 149(2): 440-448

Synthesis of acetyl coenzyme A from carbon monoxide, methyltetrahydrofolate, and coenzyme A by enzymes from Clostridium thermoaceticum.

ABSTRACT

Two purified fractions from Clostridium thermoaceticum are shown to catalyze the following reaction: CO + CH3THF + CoA ATP leads to CH3COCoA + THF. The methyltetrahydrofolate (CH3THF) gives rise to the methyl group of the acetyl-coenzyme A (CoA) and the carbon monoxide (CO) and CoA to its carboxyl thio ester group. The role of ATP is unknown. One of the protein fractions (F2) is a methyltransferase, whereas the other fraction (F3) contains CO dehydrogenase and a methyl acceptor which is postulated to be a corrinoid enzyme. The methyltransferase catalyzes the transfer of the methyl group to the methyl acceptor, and the CO is converted to a formyl derivative by the CO dehydrogenase. By a mechanism that is as yet unknown, the formyl derivative in combination with CoA and the methyl of the methyl acceptor are converted to acetyl-CoA. It is also shown that fraction F3 catalyzes the reversible exchange of 14C from [1-14C]acetyl-CoA into 14CO and that ATP is required, but not the methyltransferase. It is proposed that these reactions are part of the mechanism which enables certain autotrophic bacteria to grow on CO. It is postulated that CH3THF is synthesized from CO and tetrahydrofolate which then, as described above, is converted to acetyl-CoA. The acetyl-CoA then serves as a precursor in other anabolic reactions. A similar autotropic pathway may occur in bacteria which grow on carbon dioxide and hydrogen.

This article has been cited by other articles:

• Doukov, T. I., Iverson, T. M., Seravalli, J., Ragsdale, S. W., Drennan, C. L. (2002). A Ni-Fe-Cu Center in a Bifunctional Carbon Monoxide Dehydrogenase/ Acetyl-CoA Synthase. Science 298: 567-572 [Abstract] [Full Text]  
• Evans, J., Tolman, C., Roberts, M. (1986). Indirect observation by 13C NMR spectroscopy of a novel CO2 fixation pathway in methanogens. Science 231: 488-491 [Abstract]