Histidine Ammonia-Lyase

**Definition:** An enzyme that catalyzes the first step of histidine catabolism, forming UROCANIC ACID and AMMONIA from HISTIDINE. Deficiency of this enzyme is associated with elevated levels of serum histidine and is called histidinemia (AMINO ACID METABOLISM, INBORN ERRORS).

**Tree numbers:** - D08.811.520.232.400.500

**Synonyms:** - Histidase - Histidinase - Histidine alpha-Deaminase - Histidine Deaminase