3HIE

Structure of the membrane-binding domain of the Sec3 subunit of the Exocyst complex

Summary for 3HIE

• Entry DOI: 10.2210/pdb3hie/pdb
• Descriptor: Exocyst complex component SEC3, PHOSPHATE ION (3 entities in total)
• Functional Keywords: ph domain, dimer, domain swapping, phosphate-binding, coiled coil, exocytosis, phosphoprotein, protein transport, transport, lipid binding protein
• Biological source: Saccharomyces cerevisiae (yeast)
• Total number of polymer chains: 4
• Total formula weight: 80524.56

Authors

Baek, K.,Dominguez, R. (deposition date: 2009-05-19, release date: 2010-02-23, Last modification date: 2024-11-27)

Primary citation

Baek, K.,Knodler, A.,Lee, S.H.,Zhang, X.,Orlando, K.,Zhang, J.,Foskett, T.J.,Guo, W.,Dominguez, R.
Structure-function study of the N-terminal domain of exocyst subunit Sec3.
J.Biol.Chem., 285:10424-10433, 2010

PubMed Abstract: The exocyst is an evolutionarily conserved octameric complex involved in polarized exocytosis from yeast to humans. The Sec3 subunit of the exocyst acts as a spatial landmark for exocytosis through its ability to bind phospholipids and small GTPases. The structure of the N-terminal domain of Sec3 (Sec3N) was determined ab initio and defines a new subclass of pleckstrin homology (PH) domains along with a new family of proteins carrying this domain. Respectively, N- and C-terminal to the PH domain Sec3N presents an additional alpha-helix and two beta-strands that mediate dimerization through domain swapping. The structure identifies residues responsible for phospholipid binding, which when mutated in cells impair the localization of exocyst components at the plasma membrane and lead to defects in exocytosis. Through its ability to bind the small GTPase Cdc42 and phospholipids, the PH domain of Sec3 functions as a coincidence detector at the plasma membrane.

PubMed: 20139078
DOI: 10.1074/jbc.M109.096966

Experimental method

X-RAY DIFFRACTION (2 Å)