Reaction: (1) an acyl-CoA + L-tryptophan = an N-acyl-L-tryptophan + CoA
(2) an acyl-CoA + L-tyrosine = an N-acyl-L-tyrosine + CoA
(3) an acyl-CoA + L-phenylalanine = an N-acyl-L-phenylalanine + CoA
Glossary: an oxazolone = an oxazole compound with a keto group attached to the ring
an oxazole = an azole compound based on a five-membered heterocyclic aromatic skeleton with an oxygen and a nitrogen separated by one carbon
Other name(s): tyzA (gene name); oxzA (gene name); trzA (gene name)
Systematic name: acyl-CoA:aromatic amino acid N-acetyltransferase
Comments: The enzyme catalyses the first step in the biosynthesis of oxazolone compounds (phenazolones, tyrazolones, and tryptazolones), which have been reported from Gram-negative as well as Gram-positive bacteria. The enzymes from different organisms have different specificity for the amino acid substrate, as well as for the length of the acyl-CoA tail.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. de Rond, T., Asay, J.E. and Moore, B.S. Co-occurrence of enzyme domains guides the discovery of an oxazolone synthetase. Nat. Chem. Biol. 17 (2021) 794-799. [PMID: 34099916]
2. Grigg, J.C., Copp, J.N., Krekhno, J.MC., Liu, J., Ibrahimova, A. and Eltis, L.D. Deciphering the biosynthesis of a novel lipid in Mycobacterium tuberculosis expands the known roles of the nitroreductase superfamily. J. Biol. Chem. 299 (2023) 104924. [PMID: 37328106]
3. Kleetz, J., Grigg, J.C., Hassan, A.A., Ibtisam, A., Copp, J.N., Lian, J., Liu, J. and Eltis, L.D. The biosynthesis of N-acylated tryptazolone in Mycobacterium tuberculosis and related bacteria. J. Biol. Chem. 302 (2026) 111079. [PMID: 41429352]