Characterization of the interaction between Trypanosoma brucei Pex5p and its receptor Pex14p.

The interaction of Trypanosoma brucei (Tb) Pex5p and its receptor TbPex14p is essential for the translocation of newly synthesized matrix proteins into the glycosome. Here, we reveal that only the third WXXXF/Y motif of TbPex5p is involved in the interaction and that negative charge of the fourth amino acid is important. We suggest that Phe35 and Phe52 of TbPex14p interact with Trp318 and Phe322 in the third motif and that the Lys56 adjacent to Phe35/Phe52 associates with the fourth Glu in the motif to make the complex. This information is expected to be useful for developing anti-trypanosomal drugs.