Recognition of peroxisomal targeting signal type 1 by the import receptor Pex5p.

Abstract

We have studied how Pex5p recognizes peroxisomal targeting signal type 1 (PTS1)-containing proteins. A randomly mutagenized pex5 library was screened in a two-hybrid setup for mutations that disrupted the interaction with the PTS1 protein Mdh3p or for suppressor mutations that could restore the interaction with Mdh3p containing a mutation in its PTS1. All mutations localized in the tetratricopeptide repeat (TPR) domain of Pex5p. The Pex5p TPR domain was modeled based on the crystal structure of a related TPR protein. Mapping of the mutations on this structural model revealed that some of the loss-of-interaction mutations consisted of substitutions in alpha-helices of TPRs with bulky amino acids, probably resulting in local misfolding and thereby indirectly preventing binding of PTS1 proteins. The other loss-of-interaction mutations and most suppressor mutations localized in short, exposed, intra-repeat loops of TPR2, TPR3, and TPR6, which are predicted to mediate direct interaction with PTS1 amino acids. Additional site-directed mutants at conserved positions in intra-repeat loops underscored the importance of the loops of TPR2 and TPR3 for PTS1 interaction. Based on the mutational analysis and the structural model, we put forward a model as to how PTS1 proteins are selected by Pex5p.

Statistics

02040'04'06'08'10'12'14'16
Citations per Year

113 Citations

Semantic Scholar estimates that this publication has 113 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Klein2001RecognitionOP, title={Recognition of peroxisomal targeting signal type 1 by the import receptor Pex5p.}, author={Adam T Klein and Phil Barnett and Gina Bottger and Danielle Konings and Henk F. Tabak and B. Distel}, journal={The Journal of biological chemistry}, year={2001}, volume={276 18}, pages={15034-41} }