4EXV: Structure of Kluyveromyces Lactis Hsv2p

Macroautophagy is essential to cell survival during starvation and proceeds by the growth of a double-membraned phagophore, which engulfs cytosol and other substrates. The synthesis and recognition of the lipid phosphatidylinositol 3-phosphate, PI(3)P, is essential for autophagy. The key autophagic PI(3)P sensors, which are conserved from yeast to humans, belong to the PROPPIN family. Here we report the crystal structure of the yeast PROPPIN Hsv2. The structure consists of a seven-bladed beta-propeller and, unexpectedly, contains two pseudo-equivalent PI(3)P binding sites on blades 5 and 6. These two sites both contribute to membrane binding in vitro and are collectively required for full autophagic function in yeast. These sites function in concert with membrane binding by a hydrophobic loop in blade 6, explaining the specificity of the PROPPINs for membrane-bound PI(3)P. These observations thus provide a structural and mechanistic framework for one of the conserved central molecular recognition events in autophagy.
PDB ID: 4EXVDownload
MMDB ID: 101063
PDB Deposition Date: 2012/5/1
Updated in MMDB: 2012/09 
Experimental Method:
x-ray diffraction
Resolution: 3  Å
Source Organism:
Similar Structures:
Biological Unit for 4EXV: monomeric; determined by author and by software (PISA)
Molecular Components in 4EXV
Label Count Molecule
Protein (1 molecule)
Svp1-like Protein 2
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB