Identification of Leishmania donovani Peroxin 14 Residues Required for Binding the Peroxin 5 Receptor Proteins

Trafficking of PTS-1 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 exception were substitutions at F40, V46, or F57 which completely abolished or increased the apparent Kd value for ldpex5 (203-391) binding by 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.

Source: BJ Cell - November 5, 2014 Category: Biochemistry Authors: H Hojjat, A Jardim Tags: BJ Biomolecules Source Type: research