Structural biology of the import pathways of peroxisomal matrix proteins.

The peroxisomal proteins (peroxins) that mediate the import of peroxisomal matrix proteins have been identified. Recently, the purification of a functional peroxisomal translocon has been reported. However, the molecular details of the import pathways and the mechanisms by which the cargo is translocated into the lumen of the organelle are still poorly understood. Structural studies have begun to provide insight into molecular mechanisms of peroxisomal import pathways for cargo proteins that harbor peroxisomal targeting signals, PTS1 and PTS2, at their C- and N-termini, respectively. So far structures have been reported for binary or tertiary protein-protein interfaces, and highlight the role of intrinsically disordered regions for these interactions. Here, we provide an overview of the currently available structural biology of peroxisomal import pathways. Current challenges and future perspectives of the structural biology of peroxisomal protein translocation are discussed.