Fig. 5.

Effects of Pex1 and Pex6 mutations on Pex15 unfolding in vitro and peroxisomal matrix-protein import in vivo. a Unfolding of the Pex15 cytosolic domain (aa 1–309) by wild-type and mutant Pex1/Pex6 was assessed by SDS-PAGE after fluorescein-5-maleimide labeling of Pex15’s buried cysteines. The percent of unfolded Pex15 (mean of n = 3) was determined by normalization to the basal labeling of Pex15 alone or in the presence of 6 M urea. For the urea control, a quarter of the total reaction was loaded on the gel. b The efficiency of peroxisome matrix-protein import in the presence of mutant Pex1 and Pex6 was tested by comparing the colony color of strains containing the violacein pathway with VioE targeted to the peroxisome. Cells with efficient protein import remain white, while defects in peroxisomal import lead to a green color development. Colonies shown are representative of n = 3 biological replicates