Biomaterial Database

Level of methionine synthase activity and interconversion of methylcobalamin and adenosylcobalamin in a facultative methylotroph, Protaminobacter ruber. 1980

K Sato, and S Shimizu

Protaminobacter ruber was cultured in a medium containing [57Co]cyanocobalamin with a "two-step cultivation method" and the forms of vitamin B12 compounds in the cells were examined. Methylcobalamin was detected in the early phases of growth and reached a maximum of about 40% of all cobalamins extracted from the cells. In the stationary phase of growth, almost all cobalamins consisted of adenosylcobalamin. Recultivation of the cells of the stationary phase in a fresh medium resulted in the conversion of adenosylcobalamin into methylcobalamin. Interconversion of methylcobalamin and adenosylcobalamin was presumed from these facts. The formation of adenosylcobalamin from methylcobalamin was demonstrated with a cell-free extract system from P. ruber. The rate of conversion of methylcobalamin into adenosylcobalamin was highest among several cobalamin analogs tested. Propylation of 5-methyltetrahydrofolate: homocysteine methyltransferase with 1-iodopropane did not affect this conversion reaction, which was probably catalyzed by methyltransferase and adenosyltransferase.

UI	MeSH Term	Description	Entries
D008780	Methyltransferases	A subclass of enzymes of the transferase class that catalyze the transfer of a methyl group from one compound to another. (Dorland, 28th ed) EC 2.1.1.	Methyltransferase
D011548	Pseudomonadaceae	A family of gram-negative bacteria usually found in soil or water and including many plant pathogens and a few animal pathogens.	Azomonas,Azomonas agilis,Azotobacteraceae
D003038	Cobamides		Deoxyadenosinecobalamins,Vitamin B 12 Coenzymes,Vitamin B12 Coenzymes,B12 Coenzymes, Vitamin,Coenzymes, Vitamin B12
D013766	5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase	An enzyme that catalyzes the formation of methionine by transfer of a methyl group from 5-methyltetrahydrofolate to homocysteine. It requires a cobamide coenzyme. The enzyme can act on mono- or triglutamate derivatives. EC 2.1.1.13.	Methionine Synthetase,Methyltetrahydrofolate Homocysteine Methyltransferase,Tetrahydropteroylglutamate Methyltransferase,Methionine Synthase,Vitamin B12-Dependent Methionine Synthase,Vitamin B12-Independent Methionine Synthase,Homocysteine Methyltransferase, Methyltetrahydrofolate,Methyltransferase, Methyltetrahydrofolate Homocysteine,Methyltransferase, Tetrahydropteroylglutamate,S-Methyltransferase, 5-Methyltetrahydrofolate-Homocysteine,Synthase, Methionine,Synthetase, Methionine
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014805	Vitamin B 12	A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.	Cobalamin,Cyanocobalamin,Cobalamins,Eritron,Vitamin B12,B 12, Vitamin,B12, Vitamin