title: Crystal structure of Leishmania tarentolae hypoxanthine-guanine phosphoribosyltransferase.
abstract: BACKGROUND
  Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) (EC 2.4.2.8) is a central enzyme in the purine recycling pathway. Parasitic protozoa of the order Kinetoplastida cannot synthesize purines de novo and use the salvage pathway to synthesize purine bases, making this an attractive target for antiparasitic drug design.
  
  
  RESULTS
  The glycosomal HGPRT from Leishmania tarentolae in a catalytically active form purified and co-crystallized with a guanosine monophosphate (GMP) in the active site. The dimeric structure of HGPRT has been solved by molecular replacement and refined against data extending to 2.1 A resolution. The structure reveals the contacts of the active site residues with GMP.
  
  
  CONCLUSIONS
  Comparative analysis of the active sites of Leishmania and human HGPRT revealed subtle differences in the position of the ligand and its interaction with the active site residues, which could be responsible for the different reactivities of the enzymes to allopurinol reported in the literature. The solution and analysis of the structure of Leishmania HGPRT may contribute to further investigations leading to a full understanding of this important enzyme family in protozoan parasites.
authors: Departamento de Física e Informática, Grupo de Cristalografia de Proteínas e Biologia Estrutural, Instituto de Física de São Carlos, USP, Caixa Postal 369, 13560-590, São Carlos - SP, Brazil. monzani@if.sc.usp.br
authors: Paulo S
authors: PS
authors: Monzani
authors: Stefano
authors: S
authors: Trapani
authors: Otavio H
authors: OH
authors: Thiemann
authors: Glaucius
authors: G
authors: Oliva
mesh_terms: D000818:Animals; D001665:Binding Sites; D018360:Crystallography, X-Ray; D019281:Dimerization; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D007891:Leishmania / Q000201:enzymology*; D008958:Models, Molecular; D010802:Phylogeny; D011487:Protein Conformation
chemical_list: D007041:Hypoxanthine Phosphoribosyltransferase