Structural basis for PI(4)P-specific membrane recruitment of the Legionella pneumophila effector DrrA/SidM
Program in Molecular Medicine; Department of Biochemistry and Molecular Pharmacology
Bacterial Proteins; Binding Sites; Cell Membrane; Crystallography, X-Ray; Guanine Nucleotide Exchange Factors; Legionella pneumophila; Models, Molecular; Phosphatidylinositol Phosphates; Protein Conformation
Biochemistry | Molecular Biology | Molecular Genetics | Structural Biology
Recruitment of the Legionella pneumophila effector DrrA to the Legionella-containing vacuole, where it activates and AMPylates Rab1, is mediated by a P4M domain that binds phosphatidylinositol 4-phosphate [PI(4)P] with high affinity and specificity. Despite the importance of PI(4)P in Golgi trafficking and its manipulation by pathogens, the structural bases for PI(4)P-dependent membrane recruitment remain poorly defined. Here, we determined the crystal structure of a DrrA fragment including the P4M domain in complex with dibutyl PI(4)P and investigated the determinants of phosphoinositide recognition and membrane targeting. Headgroup recognition involves an elaborate network of direct and water-mediated interactions with basic and polar residues in the context of a deep, constrictive binding pocket. An adjacent hydrophobic helical element packs against the acyl chains and inserts robustly into PI(4)P-containing monolayers. The structural, biochemical, and biophysical data reported here support a detailed structural mechanism for PI(4)P-dependent membrane targeting by DrrA.
DOI of Published Version
Structure. 2014 Mar 4;22(3):397-408. doi: 10.1016/j.str.2013.12.018. Epub 2014 Feb 13. Link to article on publisher's site
Structure (London, England : 1993)
Del Campo, Claudia M.; Mishra, Ashwini K.; Wang, Yu-Hsiu; Roy, Craig R.; Janmey, Paul A.; and Lambright, David G., "Structural basis for PI(4)P-specific membrane recruitment of the Legionella pneumophila effector DrrA/SidM" (2014). Program in Molecular Medicine Publications and Presentations. 64.