| Synonyms |
ammonia-lyase, histidine, HAL, HAL1, Hal2, histidase, histidase, Hut, histidinase, histidinase-2, histidine alpha-deaminase, histidine ammonia lyase, histidine ammonia-lyase, histidine ammonia-lyase 2, histidine deaminase, L-HAL, L-histidase, L-histidine NH3-lyase |
| Comments |
This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC?4.3.1.23?(tyrosine 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 [4]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [5]. This enzyme catalyses the first step in the degradation of histidine and the product, urocanic acid, is further metabolized to glutamate [2,3]. |
