Reaction: L-tyrosine = trans-p-hydroxycinnamate + NH3
Other name(s): TAL; tyrase; L-tyrosine ammonia-lyase
Systematic name: L-tyrosine ammonia-lyase (trans-p-hydroxycinnamate-forming)
Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 22.214.171.124 (histidine ammonia-lyase), EC 126.96.36.199 (phenylalanine ammonia-lyase) and EC 188.8.131.52 (phenylalanine/tyrosine ammonia-lyase). The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family . This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine . The enzyme is far more active with tyrosine than with phenylalanine as substrate, but the substrate specificity can be switched by mutation of a single amino acid (H89F) in the enzyme from the bacterium Rhodobacter sphaeroides [1,2].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 1030840-68-6
1. Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327-1338. [PMID: 17185228]
2. Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317-1326. [PMID: 17185227]
3. Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355-5361. [PMID: 10220322]