S-Adenosyl methionine (SAM), also known under the commercial names of SAMe, SAM-e, or AdoMet, is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur throughout the body, most SAM is produced and consumed in the liver. More than 40 methyl transfers from SAM are known, to various substrates such as nucleic acids, proteins, lipids and secondary metabolites. It is made from adenosine triphosphate (ATP) and methionine by methionine adenosyltransferase. SAM was first discovered by Giulio Cantoni in 1952.
Methylenetetrahydrofolatereductase (MTHFR) is the rate-limiting enzyme in the methyl cycle, and it is encoded by the MTHFR gene. Methylenetetrahydrofolate reductase catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a cosubstrate for homocysteine remethylation to methionine. Natural variation in this gene is common in otherwise healthy people. Although some variants have been reported to influence susceptibility to occlusive vascular disease, neural tube defects, Alzheimer's disease and other forms of dementia, colon cancer, and acute leukemia, findings from small early studies have not been reproduced. Some mutations in this gene are associated with methylenetetrahydrofolate reductase deficiency. Complex I deficiency with recessive spastic paraparesis has also been linked to MTHFR variants. In addition, the aberrant promoter hypermethylation of this gene is associated with male infertility and recurrent spontaneous abortion.
5,10-Methylenetetrahydrofolate (N5,N10-Methylenetetrahydrofolate; 5,10-CH2-THF) is cofactor in several biochemical reactions. It exists in nature as the diastereoisomer [6R]-5,10-methylene-THF.
10-Formyltetrahydrofolate (10-CHO-THF) is a form of tetrahydrofolate that acts as a donor of formyl groups in anabolism. In these reactions 10-CHO-THF is used as a substrate in formyltransferase reactions.
dCMP deaminase is an enzyme which converts deoxycytidylic acid to deoxyuridylic acid.
In enzymology, a methylenetetrahydrofolate-tRNA-(uracil-5-)-methyltransferase (EC 2.1.1.74) is an enzyme that catalyzes the chemical reaction
In enzymology, a thymidylate synthase (FAD) (EC 2.1.1.148) is an enzyme that catalyzes the chemical reaction
In enzymology, a tRNA (uracil-5-)-methyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a methylenetetrahydrofolate dehydrogenase (NAD+) (EC 1.5.1.15) is an enzyme that catalyzes a chemical reaction.
In enzymology, a methylenetetrahydrofolate dehydrogenase (NADP+) (EC 1.5.1.5) is an enzyme that catalyzes the chemical reaction
In enzymology, a methylenetetrahydrofolate reductase (ferredoxin) (EC 1.5.7.1) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3-methyl-2-oxobutanoate hydroxymethyltransferase (EC 2.1.2.11) is an enzyme that catalyzes the chemical reaction
In enzymology, a D-alanine 2-hydroxymethyltransferase (EC 2.1.2.7) is an enzyme that catalyzes the chemical reaction
In enzymology, a deoxycytidylate 5-hydroxymethyltransferase (EC 2.1.2.8) is an enzyme that catalyzes the chemical reaction
In enzymology, a methenyltetrahydrofolate cyclohydrolase (EC 3.5.4.9) is an enzyme that catalyzes the chemical reaction
In enzymology, a cytidylate kinase is an enzyme that catalyzes the chemical reaction
Lipid IVA 3-deoxy-D-manno-octulosonic acid transferase is an enzyme with systematic name CMP-3-deoxy-D-manno-oct-2-ulosonate:lipid IVA 3-deoxy-D-manno-oct-2-ulosonate transferase. This enzyme catalyses the following chemical reaction
(KDO)-lipid IVA 3-deoxy-D-manno-octulosonic acid transferase is an enzyme with systematic name CMP-3-deoxy-D-manno-oct-2-ulosonate:(KDO)-lipid IVA 3-deoxy-D-manno-oct-2-ulosonate transferase. This enzyme catalyses the following chemical reaction
(KDO)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase is an enzyme with systematic name CMP-3-deoxy-D-manno-oct-2-ulosonate:(KDO)2-lipid IVA 3-deoxy-D-manno-oct-2-ulosonate transferase . This enzyme catalyses the following chemical reaction
(KDO)3-lipid IVA (2-4) 3-deoxy-D-manno-octulosonic acid transferase is an enzyme with systematic name CMP-3-deoxy-D-manno-oct-2-ulosonate:(KDO)3-lipid IVA 3-deoxy-D-manno-oct-2-ulosonate transferase . This enzyme catalyses the following chemical reaction
