Histidine ammonia-lyase

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HAL
Identifiers
Aliases HAL , HIS, HSTD, histidine ammonia-lyase, Histidine ammonia-lyase
External IDs OMIM: 609457; MGI: 96010; HomoloGene: 68229; GeneCards: HAL; OMA:HAL - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001258333
NM_001258334
NM_002108

NM_010401

RefSeq (protein)

NP_001245262
NP_001245263
NP_002099

NP_034531

Location (UCSC) Chr 12: 95.97 – 96 Mb Chr 10: 93.32 – 93.36 Mb
PubMed search [3] [4]
Wikidata
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histidine ammonia-lyase
1gkm.jpg
Histidine ammonia-lyase homotetramer, Pseudomonas putida
Identifiers
EC no. 4.3.1.3
CAS no. 9013-75-6
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 / QuickGO
Search
PMC articles
PubMed articles
NCBI proteins

Histidine ammonia-lyase (EC 4.3.1.3, histidase, histidinase) is an enzyme that in humans is encoded by the HAL gene. [5] [6] It converts histidine into ammonia and urocanic acid. Its systematic name is L-histidine ammonia-lyase (urocanate-forming).

Contents

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. [5] The reaction is catalyzed by 3,5-dihydro-5-methyldiene-4H-imidazol-4-one (MIO), an electrophilic cofactor which is formed autocatalytically by cyclization of the protein backbone of the enzyme. [7]

Proposed autocatalytic formation of MIO cofactor in another enzyme, phenylalanine ammonia-lyase, from the tripeptide Ala-Ser-Gly by two water elimination steps. MIO.png
Proposed autocatalytic formation of MIO cofactor in another enzyme, phenylalanine ammonia-lyase, from the tripeptide Ala-Ser-Gly by two water elimination steps.

Pathology

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

See also

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000084110 Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000020017 Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. 1 2 "Entrez Gene: histidine ammonia-lyase".
  6. Suchi M, Sano H, Mizuno H, Wada Y (September 1995). "Molecular cloning and structural characterization of the human histidase gene (HAL)". Genomics. 29 (1): 98–104. doi:10.1006/geno.1995.1219. PMID   8530107.
  7. Schwede T, Rétey J, Schulz G (Apr 27, 1999). "Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile". Biochemistry. 38 (17): 5355–5361. doi:10.1021/bi982929q. PMID   10220322.

Further reading

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