|1ore, resolution 2.10Å ()|
|Gene:||APRT (Homo sapiens)|
Human Adenine Phosphoribosyltransferase
In mammals, adenine phosphoribosyltransferase (APRT, EC 126.96.36.199) is present in all tissues and provides the only known mechanism for the metabolic salvage of adenine resulting from the polyamine biosynthesis pathway or from dietary sources. In humans, APRT deficiency results in serious kidney illness such as nephrolithiasis, interstitial nephritis, and chronic renal failure as a result of 2,8-dihydroxyadenine (DHA) precipitation in the renal interstitium. To address the molecular basis of DHA-urolithiasis, the recombinant human APRT was crystallized in complex with adenosine 5'-monophosphate (AMP). Refinement of X-ray diffraction data extended to 2.1 A resolution led to a final crystallographic R(factor) of 13.3% and an R(free) of 17.6%. This structure is composed of nine beta-strands and six alpha-helices, and the active site pocket opens slightly to accommodate the AMP product. The core of APRT is similar to that of other phosphoribosyltransferases (PRTases), although the adenine-binding domain is quite different. Structural comparisons between the human APRT and other "type I" PRTases of known structure revealed several important features of the biochemistry of PRTases. We propose that the residues located at positions corresponding to Leu159 and Ala131 in hAPRT are responsible for the base specificities of type I PRTases. The comparative analysis shown here also provides structural information for the mechanism by which mutations in the human APRT lead to DHA-urolithiasis.
Three-dimensional structure of human adenine phosphoribosyltransferase and its relation to DHA-urolithiasis., Silva M, Silva CH, Iulek J, Thiemann OH, Biochemistry. 2004 Jun 22;43(24):7663-71. PMID:15196008
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[APT_HUMAN] Defects in APRT are the cause of adenine phosphoribosyltransferase deficiency (APRTD) [MIM:614723]; also known as 2,8-dihydroxyadenine urolithiasis. An enzymatic deficiency that can lead to urolithiasis and renal failure. Patients have 2,8-dihydroxyadenine (DHA) urinary stones.
[APT_HUMAN] Catalyzes a salvage reaction resulting in the formation of AMP, that is energically less costly than de novo synthesis.
About this Structure
- Silva M, Silva CH, Iulek J, Thiemann OH. Three-dimensional structure of human adenine phosphoribosyltransferase and its relation to DHA-urolithiasis. Biochemistry. 2004 Jun 22;43(24):7663-71. PMID:15196008 doi:10.1021/bi0360758
- ↑ Chen J, Sahota A, Laxdal T, Scrine M, Bowman S, Cui C, Stambrook PJ, Tischfield JA. Identification of a single missense mutation in the adenine phosphoribosyltransferase (APRT) gene from five Icelandic patients and a British patient. Am J Hum Genet. 1991 Dec;49(6):1306-11. PMID:1746557
- ↑ Sahota A, Chen J, Boyadjiev SA, Gault MH, Tischfield JA. Missense mutation in the adenine phosphoribosyltransferase gene causing 2,8-dihydroxyadenine urolithiasis. Hum Mol Genet. 1994 May;3(5):817-8. PMID:7915931
- ↑ Hidaka Y, Palella TD, O'Toole TE, Tarle SA, Kelley WN. Human adenine phosphoribosyltransferase. Identification of allelic mutations at the nucleotide level as a cause of complete deficiency of the enzyme. J Clin Invest. 1987 Nov;80(5):1409-15. PMID:3680503 doi:http://dx.doi.org/10.1172/JCI113219
- ↑ Hidaka Y, Tarle SA, Fujimori S, Kamatani N, Kelley WN, Palella TD. Human adenine phosphoribosyltransferase deficiency. Demonstration of a single mutant allele common to the Japanese. J Clin Invest. 1988 Mar;81(3):945-50. PMID:3343350 doi:http://dx.doi.org/10.1172/JCI113408
- ↑ Kamatani N, Hakoda M, Otsuka S, Yoshikawa H, Kashiwazaki S. Only three mutations account for almost all defective alleles causing adenine phosphoribosyltransferase deficiency in Japanese patients. J Clin Invest. 1992 Jul;90(1):130-5. PMID:1353080 doi:http://dx.doi.org/10.1172/JCI115825
- ↑ Deng L, Yang M, Frund S, Wessel T, De Abreu RA, Tischfield JA, Sahota A. 2,8-Dihydroxyadenine urolithiasis in a patient with considerable residual adenine phosphoribosyltransferase activity in cell extracts but with mutations in both copies of APRT. Mol Genet Metab. 2001 Mar;72(3):260-4. PMID:11243733 doi:10.1006/mgme.2000.3142
- ↑ Taniguchi A, Tsuchida S, Kuno S, Mita M, Machida T, Ioritani N, Terai C, Yamanaka H, Kamatani N. Identification of two novel mutations in adenine phosphoribosyltransferase gene in patients with 2,8-dihydroxyadenine urolithiasis. Nucleosides Nucleotides Nucleic Acids. 2004 Oct;23(8-9):1141-5. PMID:15571218 doi:10.1081/NCN-200027393
- ↑ Nozue H, Kamoda T, Saitoh H, Ichikawa K, Taniguchi A. A Japanese boy with adenine phosphoribosyltransferase (APRT) deficiency caused by compound heterozygosity including a novel missense mutation in APRT gene. Acta Paediatr. 2011 Dec;100(12):e285-8. doi: 10.1111/j.1651-2227.2011.02371.x., Epub 2011 Jun 17. PMID:21635362 doi:10.1111/j.1651-2227.2011.02371.x