MTR（5-methyltetrahydrofolate-homocysteine methyltransferase），癌症关联基因，基因ID：4548，该基因编码5-甲基四氢叶酸同型半胱氨酸甲基转移酶。这种酶，也被称为钴胺依赖性蛋氨酸合酶，催化蛋氨酸生物合成的最后一步。mtr突变被认为是甲基钴胺缺乏互补组g的潜在原因。另外，该基因还发现了编码不同亚型的剪接转录变体。[由RefSeq提供，2014年5月]This gene encodes the 5-methyltetrahydrofolate-homocysteine methyltransferase. This enzyme， also known as cobalamin-dependent methionine synthase， catalyzes the final step in methionine biosynthesis. Mutations in MTR have been identified as the underlying cause of methylcobalamin deficiency complementation group G. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq， May 2014]。