2pyy
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Crystal Structure of the GluR0 ligand-binding core from Nostoc punctiforme in complex with (L)-glutamate
OverviewOverview
GluR0 from Nostoc punctiforme (NpGluR0) is a bacterial homologue of the, ionotropic glutamate receptor (iGluR). We have solved the crystal, structure of the ligand-binding core of NpGluR0 in complex with, l-glutamate at a resolution of 2.1 A. The structure exhibits a, noncanonical ligand interaction and two distinct subunit interfaces. The, side-chain guanidium group of Arg80 forms a salt bridge with the, gamma-carboxyl group of bound l-glutamate: in GluR0 from Synechocystis, (SGluR0) and other iGluRs, the equivalent residues are Asn or Thr, which, cannot form a similar interaction. We suggest that the local positively, charged environment and the steric constraint created by Arg80 mediate the, selectivity of l-glutamate binding by preventing the binding of positively, charged and hydrophobic amino acids. In addition, the NpGluR0, ligand-binding core forms a new subunit interface in which the two, protomers are arranged differently than the known iGluR and SGluR0 dimer, interfaces. The significance of there being two different dimer interfaces, was investigated using analytical ultracentrifugation analysis.
About this StructureAbout this Structure
2PYY is a Single protein structure of sequence from Nostoc punctiforme with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Crystal Structure of the GluR0 Ligand-Binding Core from Nostoc punctiforme in Complex with l-Glutamate: Structural Dissection of the Ligand Interaction and Subunit Interface., Lee JH, Kang GB, Lim HH, Jin KS, Kim SH, Ree M, Park CS, Kim SJ, Eom SH, J Mol Biol. 2007 Nov 6;. PMID:18164033
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