Methylenetetrahydrofolate Reductase (MTHFR)

Methylenetetrahydrofolate reductase (EC 1.5.1.20) catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a cosubstrate for homocysteine remethylation to methionine.Sequence data from the porcine DNA were then used to screen a human liver cDNA library by PCR for isolation of a partial human cDNA, the predicted amino acid sequence of which showed strong homology to porcine MTHFR and to bacterial metF genes. The encoded 656-amino acid protein is a homodimer with a total molecular mass of 150 kD. The human and mouse MTHFR proteins share approximately 90% identity.The different sized transcripts resulted from alternate transcription start sites and polyadenylation signals.