4FYG: Structural Basis For Substrate Recognition By A Novel Legionella Phosphoinositide Phosphatase

Legionella pneumophila is an opportunistic intracellular pathogen that causes sporadic and epidemic cases of Legionnaires' disease. Emerging data suggest that Legionella infection involves the subversion of host phosphoinositide (PI) metabolism. However, how this bacterium actively manipulates PI lipids to benefit its infection is still an enigma. Here, we report that the L. pneumophila virulence factor SidF is a phosphatidylinositol polyphosphate 3-phosphatase that specifically hydrolyzes the D3 phosphate of PI(3,4)P(2) and PI(3,4,5)P(3). This activity is necessary for anchoring of PI(4)P-binding effectors to bacterial phagosomes. Crystal structures of SidF and its complex with its substrate PI(3,4)P(2) reveal striking conformational rearrangement of residues at the catalytic site to form a cationic pocket that specifically accommodates the D4 phosphate group of the substrate. Thus, our findings unveil a unique Legionella PI phosphatase essential for the establishment of lipid identity of bacterial phagosomes.
PDB ID: 4FYGDownload
MMDB ID: 102266
PDB Deposition Date: 2012/7/4
Updated in MMDB: 2012/09
Experimental Method:
x-ray diffraction
Resolution: 2.82  Å
Source Organism:
Similar Structures:
Biological Unit for 4FYG: monomeric; determined by author and by software (PISA)
Molecular Components in 4FYG
Label Count Molecule
Protein (1 molecule)
Sidf, Inhibitor of Growth Family, Member 3
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB