title: The ScPex13p SH3 domain exposes two distinct binding sites for Pex5p and Pex14p.
abstract: Pex13p is an essential component of the peroxisomal protein import machinery and interacts via its C-terminal SH3 domain with the type II SH3-ligand Pex14p and the non-PXXP protein Pex5p. We report the solution structure of the SH3 domain of Pex13p from Saccharomyces cerevisiae and the identification of a novel-binding pocket, which binds a non-PXXP-peptide representing the binding site of Pex5p. Chemical shift assays revealed the binding sites for Pex5p and Pex14p ligand peptides to be distinct and spatially separated. Competition assays demonstrated that the two ligand peptides can bind simultaneously to the SH3 domain.
authors.affiliation: Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany.
authors.forename: José R
authors.initials: JR
authors.lastname: Pires
authors.forename: Xinji
authors.initials: X
authors.lastname: Hong
authors.forename: Christoph
authors.initials: C
authors.lastname: Brockmann
authors.forename: Rudolf
authors.initials: R
authors.lastname: Volkmer-Engert
authors.forename: Jens
authors.initials: J
authors.lastname: Schneider-Mergener
authors.forename: Hartmut
authors.initials: H
authors.lastname: Oschkinat
authors.forename: Ralf
authors.initials: R
authors.lastname: Erdmann
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D019151:Peptide Library; D000074401:Peroxins; D000074435:Peroxisome-Targeting Signal 1 Receptor; D020675:Peroxisomes / Q000378:metabolism*; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D018909:src Homology Domains
chemical_list: D002352:Carrier Proteins; D005656:Fungal Proteins; D008024:Ligands; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C491105:PEX13 protein, S cerevisiae; C499195:PEX14 protein, S cerevisiae; D010446:Peptide Fragments; D019151:Peptide Library; D000074401:Peroxins; D000074435:Peroxisome-Targeting Signal 1 Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins