title: Structure of the first PDZ domain of human PSD-93.
abstract: The crystal structure of the PDZ1 domain of human PSD-93 has been determined to 2.0 A resolution. The PDZ1 domain forms a crystallographic trimer that is also predicted to be stable in solution. The main contributions to the stabilization of the trimer seem to arise from interactions involving the PDZ1-PDZ2 linker region at the extreme C-terminus of PDZ1, implying that the oligomerization that is observed is not of biological significance in full-length PSD-93. Comparison of the structures of the binding cleft of PSD-93 PDZ1 with the previously reported structures of PSD-93 PDZ2 and PDZ3 as well as of the closely related human PSD-95 PDZ1 shows that they are very similar in terms of amino-acid composition. However, the cleft is significantly narrower in PSD-95. This could be part of the basis of peptide selectivity between PSD-93 PDZ1 and PSD-95 PDZ1.
authors.affiliation: Biostructural Research, Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Monica
authors.initials: M
authors.lastname: Fiorentini
authors.forename: Ann Kallehauge
authors.initials: AK
authors.lastname: Nielsen
authors.forename: Ole
authors.initials: O
authors.lastname: Kristensen
authors.forename: Jette S
authors.initials: JS
authors.lastname: Kastrup
authors.forename: Michael
authors.initials: M
authors.lastname: Gajhede
mesh_terms: D001483:Base Sequence; D018360:Crystallography, X-Ray; D017931:DNA Primers; D051528:Guanylate Kinases / Q000737:chemistry*; D006801:Humans; D008958:Models, Molecular; D054731:PDZ Domains; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry; D025521:Tumor Suppressor Proteins / Q000737:chemistry*
chemical_list: D017931:DNA Primers; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; C496468:DLG2 protein, human; D051528:Guanylate Kinases