Crystal structure of the Saccharomyces cerevisiae phosphatidylinositol-transfer protein.
Sha, B., Phillips, S.E., Bankaitis, V.A., Luo, M.(1998) Nature 391: 506-510
- PubMed: 9461221 
- DOI: https://doi.org/10.1038/35179
- Primary Citation of Related Structures:  
1AUA - PubMed Abstract: 
The yeast phosphatidylinositol-transfer protein (Sec14) catalyses exchange of phosphatidylinositol and phosphatidylcholine between membrane bilayers in vitro. In vivo, Sec14 activity is essential for vesicle budding from the Golgi complex. Here we report a three-dimensional structure for Sec14 at 2.5 A resolution. Sec14 consists of twelve alpha-helices, six beta-strands, eight 3(10)-helices and has two distinct domains. The carboxy-terminal domain forms a hydrophobic pocket which, in the crystal structure, is occupied by two molecules of n-octyl-beta-D-glucopyranoside and represents the phospholipid-binding domain. This pocket is reinforced by a string motif whose disruption in a sec14 temperature-sensitive mutant results in destabilization of the phospholipid-binding domain. Finally, we have identified an unusual surface helix that may play a critical role in driving Sec14-mediated phospholipid exchange. From this structure, we derive the first molecular clues into how a phosphatidylinositol-transfer protein functions.
Organizational Affiliation: 
Center for Macromolecular Crystallography, Department of Microbiology, University of Alabama at Birmingham, 35294, USA.