Dihydrofolate reductase

From Proteopedia

DHFR is a ubiquitous enzyme found in all organisms. The primary physiological role of DHFR is maintenance of the intracellular levels of tetrahydrofolate, a precursor of cofactors required for the biosynthesis of purines, pyrimidines, and several amino acids. The enzyme, which is the sole source of tetrahydrofolate catalyzes the reduction of 7,8-dihydrofolate (DHF) to 5,6,7,8-tetrahydrofolate (THF) by stereospecific hydride transfer from the NADPH cofactor to the C6 atom of the pterin ring with concomitant protonation at N5. Being the sole source of THF it is an Achilles’ heel of rapidly proliferating cells, making it an attractive target of several important anticancer and antimicrobial drugs such as methotrexate, trimethoprim, and pyrimethamine.