Histidine ammonia-lyase

Histidine ammonia-lyase
Identifiers
Symbols	HAL ; HIS; HSTD
External IDs	OMIM: 609457 MGI: 96010 HomoloGene: 68229 ChEMBL: 4003 GeneCards: HAL Gene
EC number	4.3.1.3
Gene ontology Molecular function • histidine ammonia-lyase activity Cellular component • cytosol Biological process • histidine catabolic process • biosynthetic process • histidine catabolic process to glutamate and formamide • histidine catabolic process to glutamate and formate • cellular nitrogen compound metabolic process • small molecule metabolic process Sources: Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	3034	15109
Ensembl	ENSG00000084110	ENSMUSG00000020017
UniProt	P42357	P35492
RefSeq (mRNA)	NM_001258333	NM_010401
RefSeq (protein)	NP_001245262	NP_034531
Location (UCSC)	Chr 12: 95.97 – 96 Mb	Chr 10: 93.49 – 93.52 Mb
PubMed search	[1]	[2]

histidine ammonia-lyase
Identifiers
EC number	4.3.1.3
CAS number	Template:CAS
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles NCBI proteins

Histidine ammonia-lyase (or histidase, or histidinase) is an enzyme that in humans is encoded by the HAL gene. Histidase converts histidine into ammonia and urocanic acid.

Function

Histidine ammonia-lyase is a cytosolic enzyme catalyzing the first reaction in histidine catabolism, the nonoxidative deamination of L-histidine to trans-urocanic acid. The reaction is catalyzed by an electrophilic co-factor which is formed autocatalytically by cyclization of the protein backbone of the enzyme.

Pathology

Mutations in the gene for histidase are associated with histidinemia and urocanic aciduria.

External links

• Histidine Ammonia-Lyase at the US National Library of Medicine Medical Subject Headings (MeSH)

This article incorporates text from the United States National Library of Medicine, which is in the public domain.