GENERAL KNOWLEDGE

Detailed explanation-1: -Dihydrofolate reductase (DHFR) catalyzes the reduction of folic acid to tetrahydrofolate (THF). A 19-bp noncoding deletion allele maps to intron 1, beginning 60 bases from the splice donor site, and has been implicated in neural tube defects and cancer, presumably by influencing folate metabolism.

Detailed explanation-2: -Folate and Vitamins B6 and B12 DHFR catalyzes the two-step reduction of folic acid, first to dihydrofolate and then to the active coenzyme THF (Fig. 39.1). The enzyme is also responsible for the conversion of dihydrofolate, which is produced in the reaction of thymidine monophosphate biosynthesis, to THF (Fig.