Understanding the Role of a Secondary Binding Site in Protein Import
Author Information
Author(s): Chris P. Williams, Nicole Schueller, Colin A. Thompson, Marlene van den Berg, Simon D. Van Haren, Ralf Erdmann, Charles S. Bond, Ben Distel, Wolfgang Schliebs, Matthias Wilmanns, Will A. Stanley
Primary Institution: EMBL-Hamburg
Hypothesis
Is the secondary binding site in sterol carrier protein 2 essential for receptor recognition by Pex5p?
Conclusion
The secondary binding site is not essential for the import of sterol carrier protein 2 into peroxisomes.
Supporting Evidence
- The PTS1 sequence is essential for binding to Pex5p.
- Mutations in the ancillary binding site did not inhibit peroxisomal import in vivo.
- Binding affinity was significantly reduced with certain mutations in the ancillary interface.
Takeaway
This study found that a second binding site in a protein isn't needed for it to get into a cell's special compartment, but it might help other proteins.
Methodology
The study used yeast two-hybrid assays, quantitative binding measurements, and in vivo translocation assays to analyze protein interactions.
Limitations
The study cannot rule out the possibility that other cargo proteins may require the ancillary binding site.
Statistical Information
P-Value
p<0.05
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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