METH rabbit pAb

catalytic activity:5-methyltetrahydrofolate + L-homocysteine = tetrahydrofolate + L-methionine.,cofactor:Binds 1 zinc ion per subunit.,cofactor:Methylcobalamin (MeCBL).,disease:Defects in MTR are the cause of methylcobalamin deficiency type G (cblG) [MIM:250940]; also known as homocystinuria-megaloblastic anemia complementation type G. It is an autosomal recessive inherited disease that causes mental retardation, macrocytic anemia, and homocystinuria. Mild deficiency in MS activity could be associated with mild hyperhomocysteinemia, a risk factor for cardiovascular disease and possibly neural tube defects. MS mutations could also be involved in tumorigenesis.,disease:Defects in MTR may be a cause of susceptibility to folate-sensitive neural tube defects (folate-sensitive NTD) [MIM:601634]. The most common NTDs are open spina bifida (myelomeningocele) and anencephaly. Genetic defects in MTR may affect the risk of spina bifida via the maternal rather than the embryonic genotype.,domain:Modular enzyme with four functionally distinct domains. The isolated Hcy-binding domain catalyzes methyl transfer from free methylcobalamin to homocysteine. The Hcy-binding domain in association with the pterin-binding domain catalyzes the methylation of cob(I)alamin by methyltetrahydrofolate and the methylation of homocysteine. The B12-binding domain binds the cofactor. The AdoMet activation domain binds S-adenosyl-L-methionine. Under aerobic conditions cob(I)alamin can be converted to inactive cob(II)alamin. Reductive methylation by S-adenosyl-L-methionine and flavodoxin regenerates methylcobalamin.,function:Catalyzes the transfer of a methyl group from methyl-cobalamin to homocysteine, yielding enzyme-bound cob(I)alamin and methionine. Subsequently, remethylates the cofactor using methyltetrahydrofolate.,miscellaneous:L-homocysteine is bound via the zinc atom.,online information:5-methyltetrahydrofolate-homocysteine methyltransferase entry,pathway:Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; L-methionine from L-homocysteine (MetH route): step 1/1.,similarity:Belongs to the vitamin-B12 dependent methionine synthase family.,similarity:Contains 1 AdoMet activation domain.,similarity:Contains 1 B12-binding domain.,similarity:Contains 1 B12-binding N-terminal domain.,similarity:Contains 1 Hcy-binding domain.,similarity:Contains 1 pterin-binding domain.,tissue specificity:Widely expressed. Expressed at the highest levels in pancreas, heart, brain, skeletal muscle and placenta. Expressed at lower levels in lung, liver and kidney.,