IUBMB Enzyme Nomenclature


Accepted name: pyrimidodiazepine synthase

Reaction: 2-amino-6-acetyl-3,7,8,9-tetrahydro-3H-pyrimido[4,5-b][1,4]diazepin-4-one + glutathione disulfide + H2O = 6-pyruvoyltetrahydropterin + 2 glutathione

For diagram of reaction click here.

Glossary: 2-amino-6-acetyl-3,7,8,9-tetrahydro-3H-pyrimido[4,5-b][1,4]diazepin-4-one = pyrimidodiazepine

Other name(s): 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)

Comments: In the reverse direction, 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 formed is an acetyldihydro derivative. Involved in the formation of the eye pigment drosopterin in Drosophila melanogaster.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, 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 (1984) 14121-14127. [PMID: 6438092]

2. Kim, J., Suh, H., Kim, S., Kim, K., Ahn, C. and Yim, J. Identification and characteristics of the structural gene for the Drosophila eye colour mutant sepia, encoding PDA synthase, a member of the ω class glutathione S-transferases. Biochem. J. 398 (2006) 451-460. [PMID: 16712527]

[EC created 1990, modified 2014]

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