| histidase | <enzyme> An enzyme of the lyase class that catalyses the reaction of l-histidine to form urocanate and ammonia. The reaction is the initial step of histidine catabolism. Genetic deficiency of the enzyme, transmitted as an autosomal recessive trait, causes histidinaemia. Chemical name: L-Histidine ammonia-lyase Registry number: EC 4.3.1.3 (12 Dec 1998) |
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