IUBMB Enzyme Nomenclature


Accepted name: albonoursin synthase

Reaction: cyclo(L-leucyl-L-phenylalanyl) + 2 O2 = albonoursin + 2 H2O2 (overall reaction)
(1a) cyclo(L-leucyl-L-phenylalanyl) + O2 = cyclo[(Z)-α,β-didehydrophenylalanyl-L-leucyl] + H2O2
(1b) cyclo[(Z)-α,β-didehydrophenylalanyl-L-leucyl] + O2 = albonoursin + H2O2

For diagram of reaction click here.

Glossary: cyclo(L-leucyl-L-phenylalanyl) = (3S,6S)-3-benzyl-6-(2-methylpropyl)piperazine-2,5-dione
cyclo[(Z)-α,β-didehydrophenylalanyl-L-leucyl] = (3Z,6S)-3-benzylidene-6-(2-methylpropyl)piperazine-2,5-dione
albonoursin = (3Z,6Z)-3-benzylidene-6-(2-methylpropylidene)piperazine-2,5-dione

Other name(s): cyclo(dipeptide):oxygen oxidoreductase; cyclic dipeptide oxidase; AlbA

Systematic name: cyclo(L-leucyl-L-phenylalanyl):oxygen oxidoreductase

Comments: A flavoprotein from the bacterium Streptomyces noursei. The enzyme can also oxidize several other cyclo dipeptides, the best being cyclo(L-tryptophyl-L-tryptophyl) and cyclo(L-phenylalanyl-L-phenylalanyl) [1,2].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Gondry, M., Lautru, S., Fusai, G., Meunier, G., Menez, A. and Genet, R. Cyclic dipeptide oxidase from Streptomyces noursei. Isolation, purification and partial characterization of a novel, amino acyl α,β-dehydrogenase. Eur. J. Biochem. 268 (2001) 1712-1721. [PMID: 11248691]

2. Lautru, S., Gondry, M., Genet, R. and Pernodet, J.L. The albonoursin gene cluster of S. noursei. Biosynthesis of diketopiperazine metabolites independent of nonribosomal peptide synthetases. Chem. Biol. 9 (2002) 1355-1364. [PMID: 12498889]

[EC created 2013]

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