Crystal structure of yeast allantoicase reveals a repeated jelly roll motif.
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.
Leulliot
Nicolas
N
Institut de Biochimie et de Biophysique Moléculaire et Cellulaire (CNRS-Unité Mixte de Recherche 8619), Université Paris-Sud, Bâtiment 430, 91405 Orsay, France.
Quevillon-Cheruel
Sophie
S
Sorel
Isabelle
I
Graille
Marc
M
Meyer
Philippe
P
Liger
Dominique
D
Blondeau
Karine
K
Janin
Joël
J
van Tilbeurgh
Herman
H
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
D014512:Ureohydrolases; C019658:allantoicase