title: Crystal structure of yeast allantoicase reveals a repeated jelly roll motif.
abstract: Allantoicase (EC 3.5.3.4) catalyzes the conversion of allantoate into ureidoglycolate and urea, one of the final steps in the degradation of purines to urea. The mechanism of most enzymes involved in this pathway, which has been known for a long time, is unknown. In this paper we describe the three-dimensional crystal structure of the yeast allantoicase determined at a resolution of 2.6 A by single anomalous diffraction. This constitutes the first structure for an enzyme of this pathway. The structure reveals a repeated jelly roll beta-sheet motif, also present in proteins of unrelated biochemical function. Allantoicase has a hexameric arrangement in the crystal (dimer of trimers). Analysis of the protein sequence against the structural data reveals the presence of two totally conserved surface patches, one on each jelly roll motif. The hexameric packing concentrates these patches into conserved pockets that probably constitute the active site.
authors.affiliation: Institut de Biochimie et de Biophysique Moléculaire et Cellulaire (CNRS-Unité Mixte de Recherche 8619), Université Paris-Sud, Bâtiment 430, 91405 Orsay, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Leulliot
authors.forename: Sophie
authors.initials: S
authors.lastname: Quevillon-Cheruel
authors.forename: Isabelle
authors.initials: I
authors.lastname: Sorel
authors.forename: Marc
authors.initials: M
authors.lastname: Graille
authors.forename: Philippe
authors.initials: P
authors.lastname: Meyer
authors.forename: Dominique
authors.initials: D
authors.lastname: Liger
authors.forename: Karine
authors.initials: K
authors.lastname: Blondeau
authors.forename: Joël
authors.initials: J
authors.lastname: Janin
authors.forename: Herman
authors.initials: H
authors.lastname: van Tilbeurgh
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012091:Repetitive Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D016415:Sequence Alignment; D014512:Ureohydrolases / Q000737:chemistry* / Q000235:genetics
chemical_list: D014512:Ureohydrolases; C019658:allantoicase