Histidine ammonia-lyase (IPR005921)

Short name: HutH

Overlapping homologous superfamilies

Family relationships


Histidine ammonia-lyase deaminates histidine to urocanic acid, the first step in histidine degradation. It is closely related to the plant enzyme phenylalanine ammonia-lyase [PMID: 10220322] but is absent in plants and viruses. This enzyme contains a unique cofactor called 4-methylidene-imidazole-5-one group (MIO), which is produced autocatalytically by a cyclization and dehydration of the three amino-acid residues alanine, serine and glycine, for its chain folding [PMID: 11796111].

GO terms

Biological Process

GO:0006548 histidine catabolic process

Molecular Function

GO:0004397 histidine ammonia-lyase activity

Cellular Component

GO:0005737 cytoplasm

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.