National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R00GM112982
米国
Other private
DFS-20-16
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R35GM128777-01
米国
National Institutes of Health/National Cancer Institute (NIH/NCI)
ACB-12002
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
AGM-12006
米国
引用
ジャーナル: Cell / 年: 2020 タイトル: LetB Structure Reveals a Tunnel for Lipid Transport across the Bacterial Envelope. 著者: Georgia L Isom / Nicolas Coudray / Mark R MacRae / Collin T McManus / Damian C Ekiert / Gira Bhabha / 要旨: Gram-negative bacteria are surrounded by an outer membrane composed of phospholipids and lipopolysaccharide, which acts as a barrier and contributes to antibiotic resistance. The systems that mediate ...Gram-negative bacteria are surrounded by an outer membrane composed of phospholipids and lipopolysaccharide, which acts as a barrier and contributes to antibiotic resistance. The systems that mediate phospholipid trafficking across the periplasm, such as MCE (Mammalian Cell Entry) transporters, have not been well characterized. Our ~3.5 Å cryo-EM structure of the E. coli MCE protein LetB reveals an ~0.6 megadalton complex that consists of seven stacked rings, with a central hydrophobic tunnel sufficiently long to span the periplasm. Lipids bind inside the tunnel, suggesting that it functions as a pathway for lipid transport. Cryo-EM structures in the open and closed states reveal a dynamic tunnel lining, with implications for gating or substrate translocation. Our results support a model in which LetB establishes a physical link between the two membranes and creates a hydrophobic pathway for the translocation of lipids across the periplasm.
温度: 291.15 K / 手法: 蒸気拡散法, シッティングドロップ法 / pH: 8.5 詳細: Crystals grew from drops consisting of 100 nL protein plus 100 nL of a reservoir solution consisting of 0.1 M Tris pH 8.5, 20% w/v PEG 1K, and were cryoprotected by supplementing the ...詳細: Crystals grew from drops consisting of 100 nL protein plus 100 nL of a reservoir solution consisting of 0.1 M Tris pH 8.5, 20% w/v PEG 1K, and were cryoprotected by supplementing the reservoir solution with 15% ethylene glycol.