EC - Pyrimidodiazepine synthase

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IntEnz Enzyme Nomenclature


Accepted name:
pyrimidodiazepine synthase
Other names:
PDA synthase
pyrimidodiazepine:oxidized-glutathione oxidoreductase (ring-opening, cyclizing)
pyrimidodiazepine:glutathione-disulfide oxidoreductase (ring-opening, cyclizing)
Systematic name:
2-amino-6-acetyl-3,7,8,9-tetrahydro-3H-pyrimido[4,5-b][1,4]diazepin-4-one:glutathione-disulfide oxidoreductase (ring-opening, cyclizing)



In the reverse direction of reaction, the reduction of 6-pyruvoyl-tetrahydropterin is accompanied by the opening of the 6-membered pyrazine ring and the formation of the 7-membered diazepine ring. The pyrimidodiazepine involved is an acetyldihydro derivative. Involved in the formation of the eye pigment drosopterin in Drosophila melanogaster.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004734
CAS Registry Number: 93586-06-2


  1. Wiederrecht, G.J. and Brown, G.M.
    Purification and properties of the enzymes from Drosophila melanogaster that catalyze the conversion of dihydroneopterin triphosphate to the pyrimidodiazepine precursor of the drosopterins.
    J. Biol. Chem. 259 : 14121-14127 (1984). [PMID: 6438092]
  2. Kim, J., Suh, H., Kim, S., Kim, K., Ahn, C., Yim, J.
    Identification and characteristics of the structural gene for the Drosophila eye colour mutant sepia, encoding PDA synthase, a member of the omega class glutathione S-transferases.
    Biochem. J. 398 : 451-460 (2006). [PMID: 16712527]

[EC created 1990, modified 2014]