An indirect role of vitamin B12 in regulation of thymidylate synthase in Lactobacillus leichmannii
Nair, C.P.; Noronha, J.M.
Indian Journal of Experimental Biology 29(12): 1112-1115
1991
ISSN/ISBN: 0019-5189 PMID: 1816094 Document Number: 376571
Vitamin B12 augments thymidylate synthase function in L. leichmannii by facilitating indirectly the availability of suitable nonmethylpolyglutamylfolate cofactors. This is effected by the demethylation of trapped methyltetrahydrofolates, catalysed by a vitamin B12 requiring methionine synthase. Deoxyuridine supplemented cells, lacking in B12, have decreased levels of methionine synthase and thymidylate synthase. Addition of active and inactive conjugase preparation as a source of mono and polyglutamylfolates indicated that the latter are the preferred cofactors for thymidylate synthase.