Formyl transfer reactions play a key role in the construction of the purine heterocycle during de novo purine biosynthesis. Formylation is catalyzed early in the pathway by the purN glycinamide ribonucleotide transformylase (GAR Transformylase, EC 18.104.22.168) in a tetrahydrofolate-dependent manner and also by the purT GAR transformylase in a tetrahydrofolate-independent manner in bacteria. Late in the pathway, 5-aminoimidazole-4-carboxamide ribonucleotide transformylase (AICAR Transformylase, EC 22.214.171.124) catalyzes the second and final formylation involved in purine nucleotide biosynthesis. This article summarizes the salient properties and mechanistic knowledge on the transformylases with special emphasis on the mechanism of the purN GAR transformylase as explored by mutagenesis studies.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)