Crystal structure of E. coli lipoprotein diacylglyceryl transferase
Mao, G., Zhao, Y., Kang, X., Li, Z., Zhang, Y., Wang, X., Sun, F., Sankaran, K., Zhang, X.C.(2016) Nat Commun 7: 10198-10198
- PubMed: 26729647 
- DOI: https://doi.org/10.1038/ncomms10198
- Primary Citation of Related Structures:  
5AZB, 5AZC - PubMed Abstract: 
Lipoprotein biogenesis is essential for bacterial survival. Phosphatidylglycerol:prolipoprotein diacylglyceryl transferase (Lgt) is an integral membrane enzyme that catalyses the first reaction of the three-step post-translational lipid modification. Deletion of the lgt gene is lethal to most Gram-negative bacteria. Here we present the crystal structures of Escherichia coli Lgt in complex with phosphatidylglycerol and the inhibitor palmitic acid at 1.9 and 1.6?? resolution, respectively. The structures reveal the presence of two binding sites and support the previously reported structure-function relationships of Lgt. Complementation results of lgt-knockout cells with different mutant Lgt variants revealed critical residues, including Arg143 and Arg239, that are essential for diacylglyceryl transfer. Using a GFP-based in vitro assay, we correlated the activities of Lgt with structural observations. Together, the structural and biochemical data support a mechanism whereby substrate and product, lipid-modified lipobox-containing peptide, enter and leave the enzyme laterally relative to the lipid bilayer.
Organizational Affiliation: 
National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.