Figure 23-16
Regeneration of N5 N10-methylenetetrahydrofolate.
The DHF product of the thymidylate synthase reaction is converted back to N5 n10-methylene-THF by the sequential actions of
1.dihydrofolate reductase and
2) serine hydroxymethyltransferase.
The sites of action of some inhibitors are by red octagons Thymidylate synthase is inhibited by FdUMP whereas dilaydrofolate aminopterin and trime thoorm reductase is inhibited by the antifolates methotrexate,aminopterin,and trimethoprim (Box 23-1).