Histidine ammonia-lyase explained

histidine ammonia-lyase
Ec Number:	4.3.1.3
Cas Number:	9013-75-6
Go Code:	0004397
Width:	270

Histidine ammonia-lyase (histidase, histidinase) is an enzyme that in humans is encoded by the HAL gene.^{[1] [2]} It converts histidine into ammonia and urocanic acid. Its systematic name is L-histidine ammonia-lyase (urocanate-forming).

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.^[1] 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.^[3]

Pathology

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

See also

• Phenylalanine ammonia-lyase, another enzyme that contains the MIO cofactor

Further reading

• Suchi M, Harada N, Wada Y, Takagi Y . Molecular cloning of a cDNA encoding human histidase . Biochim. Biophys. Acta . 1216 . 2 . 293–5 . 1993 . 7916645 . 10.1016/0167-4781(93)90157-9.
• Davila S, Froeling FE, Tan A, etal . New genetic associations detected in a host response study to hepatitis B vaccine . Genes Immun. . 11 . 3 . 232–8 . 2010 . 20237496 . 10.1038/gene.2010.1 . 11183658 .
• Gerhard DS, Wagner L, Feingold EA, etal . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC) . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928.
• Eckhart L, Schmidt M, Mildner M, etal . Histidase expression in human epidermal keratinocytes: regulation by differentiation status and all-trans retinoic acid . J. Dermatol. Sci. . 50 . 3 . 209–15 . 2008 . 18280705 . 10.1016/j.jdermsci.2007.12.009 .
• Welsh MM, Karagas MR, Applebaum KM, etal . A role for ultraviolet radiation immunosuppression in non-melanoma skin cancer as evidenced by gene-environment interactions . Carcinogenesis . 29 . 10 . 1950–4 . 2008 . 18641401 . 10.1093/carcin/bgn160 . 2556967.
• Strausberg RL, Feingold EA, Grouse LH, etal . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2002 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . 3074035. free .
• Kawai Y, Moriyama A, Asai K, etal . Molecular characterization of histidinemia: identification of four missense mutations in the histidase gene . Hum. Genet. . 116 . 5 . 340–6 . 2005 . 15806399 . 10.1007/s00439-004-1232-5 . 33960184 .
• Taylor RG, García-Heras J, Sadler SJ, etal . Localization of histidase to human chromosome region 12q22→q24.1 and mouse chromosome region 10C2→D1 . Cytogenet. Cell Genet. . 56 . 3–4 . 178–81 . 1991 . 2055114 . 10.1159/000133082.
• Alemán G, Ortíz V, Langley E, etal . Regulation by glucagon of the rat histidase gene promoter in cultured rat hepatocytes and human hepatoblastoma cells . Am. J. Physiol. Endocrinol. Metab. . 289 . 1 . E172–9 . 2005 . 15741241 . 10.1152/ajpendo.00584.2004 .

Notes and References

1. Web site: Entrez Gene: histidine ammonia-lyase .
2. Suchi M, Sano H, Mizuno H, Wada Y . Molecular cloning and structural characterization of the human histidase gene (HAL) . Genomics . 29 . 1 . 98–104 . September 1995 . 8530107 . 10.1006/geno.1995.1219 .
3. Schwede. TF. Rétey. J. Schulz. GE. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile.. Biochemistry. Apr 27, 1999. 38. 17. 5355–5361. 10220322. 10.1021/bi982929q.