4I9T: Structure Of The H258y Mutant Of The Phosphatidylinositol-specific Phospholipase C From Staphylococcus Aureus

Peripheral membrane proteins can be targeted to specific organelles or the plasma membrane by differential recognition of phospholipid headgroups. Although molecular determinants of specificity for several headgroups, including phosphatidylserine and phosphoinositides are well defined, specific recognition of the headgroup of the zwitterionic phosphatidylcholine (PC) is less well understood. In cytosolic proteins the cation-pi box provides a suitable receptor for choline recognition and binding through the trimethylammonium moiety. In PC, this moiety might provide a sufficient handle to bind to peripheral proteins via a cation-pi cage, where the pi systems of two or more aromatic residues are within 4-5 A of the quaternary amine. We prove this hypothesis by engineering the cation-pi box into secreted phosphatidylinositol-specific phospholipase C from Staphylococcus aureus, which lacks specific PC recognition. The N254Y/H258Y variant selectively binds PC-enriched vesicles, and x-ray crystallography reveals N254Y/H258Y binds choline and dibutyroylphosphatidylcholine within the cation-pi motif. Such simple PC recognition motifs could be engineered into a wide variety of secondary structures providing a generally applicable method for specific recognition of PC.
PDB ID: 4I9TDownload
MMDB ID: 109045
PDB Deposition Date: 2012/12/5
Updated in MMDB: 2013/10
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Similar Structures:
Biological Unit for 4I9T: monomeric; determined by author and by software (PISA)
Molecular Components in 4I9T
Label Count Molecule
Protein (1 molecule)
1-phosphatidylinositol Phosphodiesterase
Molecule annotation
Chemicals (5 molecules)
* Click molecule labels to explore molecular sequence information.

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