5H28

Crystal structure of Osh1 ANK domain from Saccharomyces cerevisia

Summary for 5H28

• Entry DOI: 10.2210/pdb5h28/pdb
• Related: 5H2A 5H2C 5H2D
• Descriptor: Oxysterol-binding protein homolog 1 (2 entities in total)
• Functional Keywords: oxysterol binding, lipid transfer, ank nvj1, lipid binding protein
• Biological source: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
• Cellular location: Cytoplasm: P35845
• Total number of polymer chains: 1
• Total formula weight: 30046.47

Authors

Im, Y.J.,Manik, M.K.,Yang, H.S.,Tong, J.S. (deposition date: 2016-10-14, release date: 2017-05-17, Last modification date: 2024-03-20)

Primary citation

Manik, M.K.,Yang, H.,Tong, J.,Im, Y.J.
Structure of Yeast OSBP-Related Protein Osh1 Reveals Key Determinants for Lipid Transport and Protein Targeting at the Nucleus-Vacuole Junction
Structure, 25:617-629.e3, 2017

PubMed Abstract: Yeast Osh1 belongs to the oxysterol-binding protein (OSBP) family of proteins and contains multiple targeting modules optimized for lipid transport at the nucleus-vacuole junction (NVJ). The key determinants for NVJ targeting and the role of Osh1 at NVJs have remained elusive because of unknown lipid specificities. In this study, we determined the structures of the ankyrin repeat domain (ANK), and OSBP-related domain (ORD) of Osh1, in complex with Nvj1 and ergosterol, respectively. The Osh1 ANK forms a unique bi-lobed structure that recognizes a cytosolic helical segment of Nvj1. We discovered that Osh1 ORD binds ergosterol and phosphatidylinositol 4-phosphate PI(4)P in a competitive manner, suggesting counter-transport function of the two lipids. Ergosterol is bound to the hydrophobic pocket in a head-down orientation, and the structure of the PI(4)P-binding site in Osh1 is well conserved. Our results suggest that Osh1 performs non-vesicular transport of ergosterol and PI(4)P at the NVJ.

PubMed: 28319008
DOI: 10.1016/j.str.2017.02.010

Experimental method

X-RAY DIFFRACTION (1.5 Å)