title: Crystal structure of E. coli lipoprotein diacylglyceryl transferase.
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 Å 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.
authors.affiliation: National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Guotao
authors.initials: G
authors.lastname: Mao
authors.affiliation: National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.|School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Xusheng
authors.initials: X
authors.lastname: Kang
authors.affiliation: National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Li
authors.affiliation: National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Xianping
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Sun
authors.affiliation: Centre for Biotechnology, Anna University, Chennai 600025, India.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Sankaran
authors.affiliation: National Laboratory of Macromolecules, National Center of Protein Science - Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Xuejun C
authors.initials: XC
authors.lastname: Zhang
mesh_terms: D020134:Catalytic Domain; D003460:Crystallization; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D013379:Substrate Specificity; D014166:Transferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D008074:Lipoproteins; D014166:Transferases; C042308:phosphatidylglycerol glyceryl transferase