aminomethyltransferas

Aminomethyltransferase refers to a family of enzymes that catalyze the transfer of an aminomethyl group (−CH2NH2) from a donor molecule to an acceptor. These reactions fall within the broader class of transferases and are diverse in their substrates and biological contexts. Because the term is descriptive rather than a single conserved enzyme, several unrelated proteins may be labeled aminomethyltransferases in different species or pathways.

Mechanistically, many aminomethyltransferases operate as either pyridoxal phosphate (PLP)-dependent enzymes or as folate-dependent enzymes. PLP-dependent members typically catalyze the transfer of amino-containing methylene units through formation of enzyme-bound intermediates, while folate-dependent variants couple aminomethyl transfer to one-carbon carrier systems such as tetrahydrofolate (THF) derivatives. In these systems, the aminomethyl group may be delivered to or withdrawn from folate cofactors to participate in nucleotide biosynthesis, amino acid catabolism, or other one-carbon metabolic steps.

Structure and evolution vary among aminomethyltransferases. Many are homodimers or oligomers with active sites that bind PLP or folate cofactors, and they often feature conserved motifs typical of amine transferases. Their distribution spans bacteria, archaea, and eukaryotes, where they contribute to essential metabolic networks and adaptation to available substrates.

Nomenclature can be inconsistent, with aminomethyltransferase used as a general descriptor for several distinct enzymes. When possible, precise characterization relies on specific EC numbers, gene names, and organism context. See also related one-carbon transfer enzymes such as serine hydroxymethyltransferase and other folate-dependent enzymes.