3w15
From Proteopedia
Structure of peroxisomal targeting signal 2 (PTS2) of Saccharomyces cerevisiae 3-ketoacyl-CoA thiolase in complex with Pex7p and Pex21p
Structural highlights
Function[PEX7_YEAST] Binds to the N-terminal PTS2-type peroxisomal targeting signal and plays an essential role in peroxisomal protein import essential for import of 3-oxoacyl-CoA thiolase (a PTS2-containing protein) into peroxisomes. May direct thiolase to peroxisomes by shuttling between the cytosol and peroxisomal membranes. [PEX21_YEAST] Involved in peroxisome biogenesis and the import of peroxisomal matrix proteins that contain the peroxisomal targeting sequence PTS2. Required for peroxisomal targeting of PEX7 and growth on oleate. Acts as an activator of the seryl-tRNA synthetase SES1 by increasing its binding to tRNA.[1] [2] [3] [4] Publication Abstract from PubMedAppropriate targeting of matrix proteins to peroxisomes is mainly directed by two types of peroxisomal targeting signals, PTS1 and PTS2. Although the basis of PTS1 recognition has been revealed by structural studies, that of PTS2 recognition remains elusive. Here we present the crystal structure of a heterotrimeric PTS2-recognition complex from Saccharomyces cerevisiae, containing Pex7p, the C-terminal region of Pex21p and the PTS2 of the peroxisomal 3-ketoacyl-CoA thiolase. Pex7p forms a beta-propeller structure and provides a platform for cooperative interactions with both the amphipathic PTS2 helix and Pex21p. The C-terminal region of Pex21p directly covers the hydrophobic surfaces of both Pex7p and PTS2, and the resulting hydrophobic core is the primary determinant of stable complex formation. Together with in vivo and in vitro functional assays of Pex7p and Pex21p variants, our findings reveal the molecular mechanism of PTS2 recognition. Crystal structure of peroxisomal targeting signal-2 bound to its receptor complex Pex7p-Pex21p.,Pan D, Nakatsu T, Kato H Nat Struct Mol Biol. 2013 Aug;20(8):987-93. doi: 10.1038/nsmb.2618. Epub 2013 Jun, 30. PMID:23812376[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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