ISSN:
1432-072X
Keywords:
Key words Corrinoid protein
;
Ether cleavage
;
Hydrogenase
;
Methyltransferase
;
O-demethylase
;
Strain MC
;
Tetrahydrofolate
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The O-demethylase of the methylotrophic homoacetogenic bacterium strain MC was purified to apparent homogeneity. The enzyme system consisted of four different components that were designated A, B, C, and D according to their elution sequence from the anionic-exchange chromatography column. All four components were essentially required for catalysis of the transfer of the methyl group from phenyl methyl ethers to tetrahydrofolate. According to gel filtration and SDS-PAGE, components A and B were monomers with apparent molecular masses of approximately 26 kDa (subunit 25 kDa) and 36 (subunit 41 kDa), respectively; component C appeared to be a trimeric protein (195 kDa, subunit 67 kDa); and component D was probably a dimer (64 kDa, subunit 30 kDa). Component A contained one corrinoid per monomer. In crude extracts, component D appeared to be the rate-limiting protein for the complete methyl transfer reaction. Additional requirements for the reaction were ATP and low-potential reducing equivalents supplied by either titanium(III) citrate or H2 plus hydrogenase purified from strain MC.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002030050479
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