[HPRT_HUMAN] Defects in HPRT1 are the cause of Lesch-Nyhan syndrome (LNS) [MIM:300322]. LNS is characterized by complete lack of enzymatic activity that results in hyperuricemia, choreoathetosis, mental retardation, and compulsive self-mutilation. Defects in HPRT1 are the cause of gout HPRT-related (GOUT-HPRT) [MIM:300323]; also known as HPRT-related gout or Kelley-Seegmiller syndrome. Gout is characterized by partial enzyme activity and hyperuricemia. [:]
[HPRT_HUMAN] Converts guanine to guanosine monophosphate, and hypoxanthine to inosine monophosphate. Transfers the 5-phosphoribosyl group from 5-phosphoribosylpyrophosphate onto the purine. Plays a central role in the generation of purine nucleotides through the purine salvage pathway.
Human hypoxanthine-guanine phosphoribosyltransferase (HGPRT) catalyses the synthesis of the purine nucleoside monophosphates, IMP and GMP, by the addition of a 6-oxopurine base, either hypoxanthine or guanine, to the 1-beta-position of 5-phospho-alpha-d-ribosyl-1-pyrophosphate (PRib-PP). The mechanism is sequential, with PRib-PP binding to the free enzyme prior to the base. After the covalent reaction, pyrophosphate is released followed by the nucleoside monophosphate. A number of snapshots of the structure of this enzyme along the reaction pathway have been captured. These include the structure in the presence of the inactive purine base analogue, 7-hydroxy [4,3-d] pyrazolo pyrimidine (HPP) and PRib-PP.Mg2+, and in complex with IMP or GMP. The third structure is that of the immucillinHP.Mg(2+).PP(i) complex, a transition-state analogue. Here, the first crystal structure of free human HGPRT is reported to 1.9A resolution, showing that significant conformational changes have to occur for the substrate(s) to bind and for catalysis to proceed. Included in these changes are relative movement of subunits within the tetramer, rotation and extension of an active-site alpha-helix (D137-D153), reorientation of key active-site residues K68, D137 and K165, and the rearrangement of three active-site loops (100-128, 165-173 and 186-196). Toxoplasma gondii HGXPRT is the only other 6-oxopurine phosphoribosyltransferase structure solved in the absence of ligands. Comparison of this structure with human HGPRT reveals significant differences in the two active sites, including the structure of the flexible loop containing K68 (human) or K79 (T.gondii).
The crystal structure of free human hypoxanthine-guanine phosphoribosyltransferase reveals extensive conformational plasticity throughout the catalytic cycle.,Keough DT, Brereton IM, de Jersey J, Guddat LW J Mol Biol. 2005 Aug 5;351(1):170-81. PMID:15990111
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Wilson JM, Kelley WN. Molecular basis of hypoxanthine-guanine phosphoribosyltransferase deficiency in a patient with the Lesch-Nyhan syndrome. J Clin Invest. 1983 May;71(5):1331-5. PMID:6853716
↑ Davidson BL, Pashmforoush M, Kelley WN, Palella TD. Genetic basis of hypoxanthine guanine phosphoribosyltransferase deficiency in a patient with the Lesch-Nyhan syndrome (HPRTFlint). Gene. 1988 Mar 31;63(2):331-6. PMID:3384338
↑ Davidson BL, Palella TD, Kelley WN. Human hypoxanthine-guanine phosphoribosyltransferase: a single nucleotide substitution in cDNA clones isolated from a patient with Lesch-Nyhan syndrome (HPRTMidland). Gene. 1988 Aug 15;68(1):85-91. PMID:3265398
↑ Fujimori S, Davidson BL, Kelley WN, Palella TD. Identification of a single nucleotide change in the hypoxanthine-guanine phosphoribosyltransferase gene (HPRTYale) responsible for Lesch-Nyhan syndrome. J Clin Invest. 1989 Jan;83(1):11-3. PMID:2910902 doi:http://dx.doi.org/10.1172/JCI113846
↑ Gibbs RA, Nguyen PN, Edwards A, Civitello AB, Caskey CT. Multiplex DNA deletion detection and exon sequencing of the hypoxanthine phosphoribosyltransferase gene in Lesch-Nyhan families. Genomics. 1990 Jun;7(2):235-44. PMID:2347587
↑ Skopek TR, Recio L, Simpson D, Dallaire L, Melancon SB, Ogier H, O'Neill JP, Falta MT, Nicklas JA, Albertini RJ. Molecular analyses of a Lesch-Nyhan syndrome mutation (hprtMontreal) by use of T-lymphocyte cultures. Hum Genet. 1990 Jun;85(1):111-6. PMID:2358296
↑ Gordon RB, Sculley DG, Dawson PA, Beacham IR, Emmerson BT. Identification of a single nucleotide substitution in the coding sequence of in vitro amplified cDNA from a patient with partial HPRT deficiency (HPRTBRISBANE). J Inherit Metab Dis. 1990;13(5):692-700. PMID:2246854
↑ Tarle SA, Davidson BL, Wu VC, Zidar FJ, Seegmiller JE, Kelley WN, Palella TD. Determination of the mutations responsible for the Lesch-Nyhan syndrome in 17 subjects. Genomics. 1991 Jun;10(2):499-501. PMID:2071157
↑ Burgemeister R, Rotzer E, Gutensohn W, Gehrke M, Schiel W. Identification of a new missense mutation in exon 2 of the human hypoxanthine phosphoribosyltransferase gene (HPRTIsar): a further example of clinical heterogeneity in HPRT deficiencies. Hum Mutat. 1995;5(4):341-4. PMID:7627191 doi:http://dx.doi.org/10.1002/humu.1380050413
↑ Liu G, Aral B, Zabot MT, Kamoun P, Ceballos-Picot I. The molecular basis of hypoxanthine-guanine phosphoribosyltransferase deficiency in French families; report of two novel mutations. Hum Mutat. 1998;Suppl 1:S88-90. PMID:9452051
↑ Wilson JM, Kobayashi R, Fox IH, Kelley WN. Human hypoxanthine-guanine phosphoribosyltransferase. J Biol Chem. 1983 May 25;258(10):6458-60. PMID:6853490
↑ Wilson JM, Tarr GE, Kelley WN. Human hypoxanthine (guanine) phosphoribosyltransferase: an amino acid substitution in a mutant form of the enzyme isolated from a patient with gout. Proc Natl Acad Sci U S A. 1983 Feb;80(3):870-3. PMID:6572373
↑ Wilson JM, Kelley WN. Human hypoxanthine-guanine phosphoribosyltransferase. Structural alteration in a dysfunctional enzyme variant (HPRTMunich) isolated from a patient with gout. J Biol Chem. 1984 Jan 10;259(1):27-30. PMID:6706936
↑ Cariello NF, Scott JK, Kat AG, Thilly WG, Keohavong P. Resolution of a missense mutant in human genomic DNA by denaturing gradient gel electrophoresis and direct sequencing using in vitro DNA amplification: HPRT Munich. Am J Hum Genet. 1988 May;42(5):726-34. PMID:3358423
↑ Davidson BL, Chin SJ, Wilson JM, Kelley WN, Palella TD. Hypoxanthine-guanine phosphoribosyltransferase. Genetic evidence for identical mutations in two partially deficient subjects. J Clin Invest. 1988 Dec;82(6):2164-7. PMID:3198771 doi:http://dx.doi.org/10.1172/JCI113839
↑ Davidson BL, Pashmforoush M, Kelley WN, Palella TD. Human hypoxanthine-guanine phosphoribosyltransferase deficiency. The molecular defect in a patient with gout (HPRTAshville). J Biol Chem. 1989 Jan 5;264(1):520-5. PMID:2909537
↑ Keough DT, Brereton IM, de Jersey J, Guddat LW. The crystal structure of free human hypoxanthine-guanine phosphoribosyltransferase reveals extensive conformational plasticity throughout the catalytic cycle. J Mol Biol. 2005 Aug 5;351(1):170-81. PMID:15990111 doi:10.1016/j.jmb.2005.05.061