Glutamate formimidoyltransferase
Protein domain
From Wikipedia, the free encyclopedia
Glutamate formimidoyltransferase is a methyltransferase enzyme which uses tetrahydrofolate as part of histidine catabolism. It catalyses two reactions. In the first, N-formimidoyl-L-glutamate (from histidine) transfers its formimidoyl group to tetrahydrofolate.[1][2]
Alternatively, the enzyme can catalyse the transfer of a formyl group from N-formyl-L-glutamic acid.[2]
It is classified under EC 2.1.2.5 and in mammals is found as part of a bifunctional enzyme that also has formimidoyltetrahydrofolate cyclodeaminase activity.[3]
Structure
The formiminotransferase (FT) domain of formiminotransferase-cyclodeaminase (FTCD) forms a homodimer, with each protomer comprising two subdomains. The formiminotransferase domain has an N-terminal subdomain that is made up of a six-stranded mixed beta-pleated sheet and five alpha helices, which are arranged on the external surface of the beta sheet. This, in turn, faces the beta-sheet of the C-terminal subdomain to form a double beta-sheet layer. The two subdomains are separated by a short linker sequence, which is not thought to be any more flexible than the remainder of the molecule. The substrate is predicted to form a number of contacts with residues found in both the N-terminal and C-terminal subdomains.[4] In humans, deficiency of this enzyme results in a disease phenotype.[5]
