| EC |
4.3.1.23 |
| Accepted name: |
tyrosine ammonia-lyase |
| 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 4.3.1.3 (histidine ammonia-lyase), EC 4.3.1.24 (phenylalanine ammonia-lyase) and EC 4.3.1.25 (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 [1]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [3]. 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, PDB, CAS registry number: 1030840-68-6 |
| References: |
| 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. [DOI] [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. [DOI] [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. [DOI] [PMID: 10220322] |
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| [EC 4.3.1.23 created 2008 (EC 4.3.1.5 created 1965, part-incorporated 2008)] |
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