5-alpha reductase | HMG-CoA reductase | Rubredoxin—NAD(P)+ reductase | Ribonucleoside-triphosphate reductase | GMP reductase | Flavanone 4-reductase | D-xylose reductase |
E2F target genes encode proteins involved in DNA replication (for example DNA polymerase, thymidine kinase, dihydrofolate reductase and cdc6), and chromosomal replication (replication origin-binding protein HsOrc1 and MCM5).
Since tetrahydrofolate is needed to make both purines and pyrimidines, which are building blocks of DNA and RNA, dihydrofolate reductase is targeted by various drugs to prevent nucleic acid synthesis.