histidine ammonia-lyase; histidase (HAL, HIS)

Function

• amino-acid degradation; L-histidine degradation into L-glutamate; N-formimidoyl-L-glutamate from L-histidine: step 1/3
• contains an active site 4-methylidene-imidazol-5-one (MIO), which is formed autocatalytically by cyclization & dehydration of residues Ala-Ser-Gly (putative)

L-histidine <--> urocanate + NH3

Structure

belongs to the PAL/histidase family

Pathology

• defects in HAL are the cause of histidinemia

More general terms

• protease; proteinase; endopeptidase
• phosphoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/P42357.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=3034
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:3034
• OMIM: https://mirror.omim.org/entry/235800
• OMIM: https://mirror.omim.org/entry/609457