title: Identification of Leishmania donovani peroxin 14 residues required for binding the peroxin 5 receptor proteins.
abstract: Trafficking of peroxisomal targeting signal 1 (PTS1) proteins to the Leishmania glycosome is dependent on the docking of the LdPEX5 receptor to LdPEX14 on the glycosomal membrane. A combination of deletion and random mutagenesis was used to identify residues in the LdPEX14 N-terminal region that are critical for mediating the LdPEX5-LdPEX14 interaction. These studies highlighted residues 35-75 on ldpex14 as the core domain required for binding LdPEX5. Single point mutation within this core domain generally did not affect the ldpex5-(203-391)-ldpex14-(1-120) interaction; notable exceptions were substitutions at Phe40, Val46 or Phe57 which completely abolished or increased the apparent Kd value for ldpex5-(203-391) binding 30-fold. Biochemical studies revealed that these point mutations did not alter either the secondary or quaternary structure of LdPEX14 and indicated that the latter residues were critical for stabilizing the LdPEX5-LdPEX14 interaction.
authors.affiliation: *Institute of Parasitology and Centre for Host-Parasite Interactions, McGill University, Ste. Anne de Bellevue, Quebec, Canada, H9X 3V9.
authors.forename: Hamed
authors.initials: H
authors.lastname: Hojjat
authors.affiliation: *Institute of Parasitology and Centre for Host-Parasite Interactions, McGill University, Ste. Anne de Bellevue, Quebec, Canada, H9X 3V9.
authors.forename: Armando
authors.initials: A
authors.lastname: Jardim
mesh_terms: D019943:Amino Acid Substitution; D007893:Leishmania donovani / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016296:Mutagenesis; D017354:Point Mutation; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; C470663:PEX14 protein, Leishmania donovani; D015800:Protozoan Proteins