IUBMB Enzyme Nomenclature


Accepted name: phenylalanine ammonia-lyase

Reaction: L-phenylalanine = trans-cinnamate + NH3

For diagram of reaction click here

Other name(s): phenylalanine deaminase; phenylalanine ammonium-lyase; PAL; L-phenylalanine ammonia-lyase; Phe ammonia-lyase

Systematic name: L-phenylalanine ammonia-lyase (trans-cinnamate-forming)

Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC (histidine ammonia-lyase) and EC (tyrosine ammonia-lyase) and EC (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 [3]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [9]. The enzyme from some species is highly specific for phenylalanine [7,8].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9024-28-6


1. Koukol, J. and Conn, E.E. The metabolism of aromatic compounds in higher plants. IV. Purification and properties of the phenylalanine deaminase of Hordeum vulgare. J. Biol. Chem. 236 (1961) 2692-2698. [PMID: 14458851]

2. Young, M.R. and Neish, A.C. Properties of the ammonia-lyases deaminating phenylalanine and related compounds in Triticum sestivum and Pteridium aquilinum. Phytochemistry 5 (1966) 1121-1132.

3. 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]

4. Calabrese, J.C., Jordan, D.B., Boodhoo, A., Sariaslani, S. and Vannelli, T. Crystal structure of phenylalanine ammonia lyase: multiple helix dipoles implicated in catalysis. Biochemistry 43 (2004) 11403-11416. [PMID: 15350127]

5. Ritter, H. and Schulz, G.E. Structural basis for the entrance into the phenylpropanoid metabolism catalyzed by phenylalanine ammonia-lyase. Plant Cell 16 (2004) 3426-3436. [PMID: 15548745]

6. 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]

7. Appert, C., Logemann, E., Hahlbrock, K., Schmid, J. and Amrhein, N. Structural and catalytic properties of the four phenylalanine ammonia-lyase isoenzymes from parsley (Petroselinum crispum Nym.). Eur. J. Biochem. 225 (1994) 491-499. [PMID: 7925471]

8. Cochrane, F.C., Davin, L.B. and Lewis, N.G. The Arabidopsis phenylalanine ammonia lyase gene family: kinetic characterization of the four PAL isoforms. Phytochemistry 65 (2004) 1557-1564. [PMID: 15276452]

9. 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]

[EC created 2008 (EC created 1965, part-incorporated 2008)]

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