the enzyme catalyzes P-methylation using radical S-adenosyl-L-methionine-dependent chemistry with cobalamin as a coenzymemethyl donor of the reaction. The enzyme is active in the absence of methylcobalamin if the strong reductant titanium(III)citrate and hydroxocobalamin are provided
the enzyme is a radical S-adenosyl-L-methionine enzyme that contains a [4Fe-4S] center and a methylcob(III)alamin cofactor. According to the proposed mechanism, the reduced iron-sulfur center donates an electron to S-adenosyl-L-methionine, resulting in homolytic cleavage of the carbon-sulfur bond to form a 5'-deoxyadenosyl radical that abstracts the hydrogen atom from the P-H bond of the substrate, forming a phosphinate-centered radical. This radical reacts with methylcob(III)alamin to produce the methylated product and cob(II)alamin, which is reduced by an unknown donor to cob(I)alamin. A potential route for restoring the latter back to methylcob(III)alamin is a nucleophilic attack on a second S-adenosyl-L-methionine molecule
the addition of 0.05 mM methylcob(III)alamin to the crude extract results in an about 6fold increase in activity which is not greatly affected by the addition of cytochrome P450 reductase or reductase domain of neuronal nitric oxide synthase
Methanol:coenzyme M methyltransferase from Methanosarcina barkeri. Zinc dependence and thermodynamics of the methanol:cob(I)alamin methyltransferase reaction
Mechanism of transfer of the methyl group from (6S)-methyltetrahydrofolate to the corrinoid/iron-sulfur protein catalyzed by the methyltransferase from Clostridium thermoaceticum: a key step in the Wood-Ljungdahl pathway of acetyl-CoA synthesis
Spectroscopic characterization and mechanistic investigation of P-methyl transfer by a radical SAM enzyme from the marine bacterium Shewanella denitrificans OS217
HOME
login
history
all enzymes
BRENDA home
close all tables 
open all tables
top
Information
