The Escherichia coli purT encoded glycinamide ribonucleotide transformylase (GAR transformylase) serves as an alternate enzyme in the production of formyl GAR for use in de novo purine biosynthesis. This enzyme differs from the previously known purN encoded enzyme in size, sequence, and substrates; ATP and formate are required as opposed to formyl tetrahydrofolate. Kinetic studies of the wild-type PurT enzyme described here demonstrate that formyl phosphate behaves as a chemically and kinetically competent intermediate. The requirement for ATP and GAR in these reactions is consistent with previous steady-state kinetic results, which demonstrated that all substrates must be bound before catalysis. Kinetic characterization of a mutant, which releases formyl phosphate into solution, and positional isotope exchange studies also support the assignment of formyl phosphate as a plausible intermediate.
Synthetase Inhibitors. -Starting with a micromolar lead identified from high-throughput screening, a series of pyrazoles [cf. (VIII), (IX)] are discovered with significantly improved potency on bacterial methionyl-tRNA synthetase and selectivity over human methionyl-tRNA synthetase. -(FINN*, J.; MATTIA, K.; MORYTKO, M.; RAM, S.; YANG, Y.; WU, X.; MAK, E.; GALLANT, P.; KEITH, D.; Bioorg.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.