1ypp
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ACID ANHYDRIDE HYDROLASE
OverviewOverview
The three-dimensional structure of the manganese-phosphate complex of, inorganic pyrophosphatase from Saccharomyces cerevisiae has been refined, to an R factor of 19.0% at 2.4-A resolution. X-ray data were collected, from a single crystal using an imaging plate scanner and synchrotron, radiation. There is one dimeric molecule in the asymmetric unit. The upper, estimate of the root-mean-square coordinate error is 0.4 A using either, the delta A plot or the superposition of the two crystallographically, independent subunits. The good agreement between the coordinates of the, two subunits, which were not subjected to non-crystallographic symmetry, restraints, provides independent validation of the structure analysis. The, active site in each subunit contains four manganese ions and two, phosphates. The manganese ions are coordinated by the side chains of, aspartate and glutamate residues. The phosphate groups, which were, identified on the basis of their local stereochemistry, interact either, directly or via water molecules with manganese ions and lysine, arginine, and tyrosine side chains. The phosphates are bridged by two of the, manganese ions. The outer phosphate is exposed to solvent. The inner, phosphate is surrounded by all four manganese ions. The ion-binding sites, are related to the order of binding previously established from kinetic, studies. A hypothesis for the transition state of the catalytic reaction, is put forward.
About this StructureAbout this Structure
1YPP is a Single protein structure of sequence from Saccharomyces cerevisiae with MN and PO4 as ligands. Active as Inorganic diphosphatase, with EC number 3.6.1.1 Full crystallographic information is available from OCA.
ReferenceReference
X-ray structure of yeast inorganic pyrophosphatase complexed with manganese and phosphate., Harutyunyan EH, Kuranova IP, Vainshtein BK, Hohne WE, Lamzin VS, Dauter Z, Teplyakov AV, Wilson KS, Eur J Biochem. 1996 Jul 1;239(1):220-8. PMID:8706712
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