6MHU
Nucleotide-free Cryo-EM Structure of E.coli LptB2FG Transporter
Summary for 6MHU
| Entry DOI | 10.2210/pdb6mhu/pdb |
| Related | 6MHU 6MHZ |
| EMDB information | 9118 9124 |
| Descriptor | Lipopolysaccharide export system permease protein LptF, Lipopolysaccharide export system permease protein LptG, Lipopolysaccharide export system ATP-binding protein LptB, ... (4 entities in total) |
| Functional Keywords | abc transporter, lipopolysaccharide, lps, nanodisc, transport protein-hydrolase complex, transport protein/hydrolase |
| Biological source | Escherichia coli (strain K12) More |
| Total number of polymer chains | 4 |
| Total formula weight | 139282.24 |
| Authors | Orlando, B.J.,Li, Y.,Liao, M. (deposition date: 2018-09-18, release date: 2019-04-03, Last modification date: 2025-05-14) |
| Primary citation | Li, Y.,Orlando, B.J.,Liao, M. Structural basis of lipopolysaccharide extraction by the LptB2FGC complex. Nature, 567:486-490, 2019 Cited by PubMed Abstract: In Gram-negative bacteria, lipopolysaccharide is essential for outer membrane formation and antibiotic resistance. The seven lipopolysaccharide transport (Lpt) proteins A-G move lipopolysaccharide from the inner to the outer membrane. The ATP-binding cassette transporter LptBFG, which tightly associates with LptC, extracts lipopolysaccharide out of the inner membrane. The mechanism of the LptBFG-LptC complex (LptBFGC) and the role of LptC in lipopolysaccharide transport are poorly understood. Here we characterize the structures of LptBFG and LptBFGC in nucleotide-free and vanadate-trapped states, using single-particle cryo-electron microscopy. These structures resolve the bound lipopolysaccharide, reveal transporter-lipopolysaccharide interactions with side-chain details and uncover how the capture and extrusion of lipopolysaccharide are coupled to conformational rearrangements of LptBFGC. LptC inserts its transmembrane helix between the two transmembrane domains of LptBFG, which represents a previously unknown regulatory mechanism for ATP-binding cassette transporters. Our results suggest a role for LptC in achieving efficient lipopolysaccharide transport, by coordinating the action of LptBFG in the inner membrane and Lpt protein interactions in the periplasm. PubMed: 30894744DOI: 10.1038/s41586-019-1025-6 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (4 Å) |
Structure validation
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