The peroxisomal receptor Pex19p forms a helical mPTS recognition domain |
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Authors: | Krisztian Fodor Morlin Milewski Petr Konarev Janina Wolf Ralf Erdmann Wolfgang Schliebs Young‐Hwa Song Matthias Wilmanns |
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Institution: | 1. EMBL c/o DESY, Notkestrasse 85, Hamburg, Germany;2. Department of Systems Biology, Faculty of Medicine, Institute for Physiological Chemistry, Ruhr University of Bochum, Bochum, Germany |
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Abstract: | The protein Pex19p functions as a receptor and chaperone of peroxisomal membrane proteins (PMPs). The crystal structure of the folded C‐terminal part of the receptor reveals a globular domain that displays a bundle of three long helices in an antiparallel arrangement. Complementary functional experiments, using a range of truncated Pex19p constructs, show that the structured α‐helical domain binds PMP‐targeting signal (mPTS) sequences with about 10 μM affinity. Removal of a conserved N‐terminal helical segment from the mPTS recognition domain impairs the ability for mPTS binding, indicating that it forms part of the mPTS‐binding site. Pex19p variants with mutations in the same sequence segment abolish correct cargo import. Our data indicate a divided N‐terminal and C‐terminal structural arrangement in Pex19p, which is reminiscent of a similar division in the Pex5p receptor, to allow separation of cargo‐targeting signal recognition and additional functions. |
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Keywords: | biogenesis peroxisome receptor structural biology translocation |
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