dihydropteridine reductase (HDHPR, quinoid dihydropteridine reductase, QDPR, DHPR)

Function

• product of this enzyme, tetrahydrobiopterin (BH-4), is an essential cofactor for
  • phenylalanine hydroxylase
  • tyrosine hydroxylase
  • tryptophan hydroxylase

5,6,7,8-tetrahydropteridine + NAD+/NADP+
             <-->
6,7-dihydropteridine + NADH/NADPH

Inhibited by trimethoprim

Structure

• homodimer
• belongs to the short-chain dehydrogenases/reductases (SDR) family

Pathology

• defects in QDPR are the cause of phenylketonuria 2

Laboratory

• dihydropteridine reductase in erythrocytes

More general terms

• oxidoreductase

Database

• UniProt: http://www.uniprot.org/uniprot/P09417.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5860
• OMIM: https://mirror.omim.org/entry/261630