5-Methyltetrahydrofolate:corrinoid/iron-sulfur protein Co-methyltransferase explained

5-methyltetrahydrofolate:corrinoid/iron-sulfur protein Co-methyltransferase
Ec Number:	2.1.1.258

5-methyltetrahydrofolate:corrinoid/iron-sulfur protein Co-methyltransferase (acsE (gene)) is an enzyme with systematic name 5-methyltetrahydrofolate:corrinoid/iron-sulfur protein methyltransferase.^{[1] [2] [3]} This enzyme catalyses the following chemical reaction

\rightleftharpoons a [Co(I) corrinoid Fe-S protein] + 5-methyltetrahydrofolate

This enzyme catalyses the transfer of a carbon atom and associated hydrogen atoms from the N⁵ position of methyltetrahydrofolate to the 5-methoxybenzimidazolylcobamide cofactor of a corrinoid/Fe-S protein, containing a corrin ring similar to that in cobalamin. Although called a methyl transferase, the net transfer is of one carbon atom and two hydrogen atomsthe methyltetrahydrofolate contains only two hydrogen atoms more than the tetrahydrofolate. The cobalt atom is able to change oxidation state by obtaining electrons frpm the 4Fe-4S complex in the protein.^[4]

Notes and References

1. Roberts DL, Zhao S, Doukov T, Ragsdale SW . The reductive acetyl coenzyme A pathway: sequence and heterologous expression of active methyltetrahydrofolate:corrinoid/iron-sulfur protein methyltransferase from Clostridium thermoaceticum . Journal of Bacteriology . 176 . 19 . 6127–30 . October 1994 . 7928975 . 196833 . 10.1128/jb.176.19.6127-6130.1994 .
2. Doukov T, Seravalli J, Stezowski JJ, Ragsdale SW . Crystal structure of a methyltetrahydrofolate- and corrinoid-dependent methyltransferase . Structure . 8 . 8 . 817–30 . August 2000 . 10997901 . 10.1016/s0969-2126(00)00172-6 . free .
3. Doukov TI, Hemmi H, Drennan CL, Ragsdale SW . Structural and kinetic evidence for an extended hydrogen-bonding network in catalysis of methyl group transfer. Role of an active site asparagine residue in activation of methyl transfer by methyltransferases . The Journal of Biological Chemistry . 282 . 9 . 6609–6618 . March 2007 . 17172470 . 3966722 . 10.1074/jbc.m609828200 . free .
4. Stephen Ragsdale and Elizabeth Pierce. Acetogenesis and the Wood-Ljungdahl pathway of CO(2) fixation . Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics . 1784 . 12 . 1873–1898 . December 2008 . 18801467 . 2646786 . 10.1016/j.bbapap.2008.08.012 .