formyltransferases

Formyltransferases are enzymes that catalyze the transfer of a formyl group (−CHO) from donor to acceptor substrates. In biological systems, the donor is often N10-formyltetrahydrofolate, a one-carbon donor derived from folate metabolism. The acceptor can be diverse, including amino groups on tRNA, or nitrogen atoms on small-molecule intermediates in nucleotide synthesis.

Several well-known formyltransferases occur in metabolism and protein synthesis. Glycinamide ribonucleotide formyltransferase (GARFT, EC 2.1.2.9) transfers a formyl group to GAR to form FGAR in purine nucleotide biosynthesis. AICAR transformylase (also called 5-aminoimidazole-4-carboxamide ribonucleotide transformylase) adds a formyl group to AICAR, producing FAICAR, a step in purine biosynthesis. tRNA formyltransferase (FMT) catalyzes formylation of the initiator tRNA met, generating formylmethionyl-tRNAiMet required for initiation in many bacteria.

Mechanism and diversity: Formyltransferases share the use of N10-formyltetrahydrofolate as the common one-carbon donor, but they act on different acceptor substrates and have diverse structural families. Some act in cytosolic pathways; others function in organelles such as mitochondria or chloroplasts.

Importance and applicability: The activity of formyltransferases links folate metabolism to both nucleotide biosynthesis and protein synthesis. Because of their essential roles in bacteria and in organellar translation, formyltransferases are of interest in basic biology and as potential targets for antimicrobial or antiparasitic strategies.