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-Structure paper
タイトル | LetB Structure Reveals a Tunnel for Lipid Transport across the Bacterial Envelope. |
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ジャーナル・号・ページ | Cell, Vol. 181, Issue 3, Page 653-664.e19, Year 2020 |
掲載日 | 2020年4月30日 |
著者 | Georgia L Isom / Nicolas Coudray / Mark R MacRae / Collin T McManus / Damian C Ekiert / Gira Bhabha / |
PubMed 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. |
リンク | Cell / PubMed:32359438 / PubMed Central |
手法 | EM (単粒子) / X線回折 |
解像度 | 2.15 - 3.78 Å |
構造データ | EMDB-20993: Lipophilic Envelope-spanning Tunnel B (LetB), Map 1 EMDB-20994: Lipophilic Envelope-spanning Tunnel B (LetB), Map 2 EMDB-20995: Lipophilic Envelope-spanning Tunnel B (LetB), Map 3 EMDB-20996: Lipophilic Envelope-spanning Tunnel B (LetB), Map 4 EMDB-20997: Lipophilic Envelope-spanning Tunnel B (LetB), Map 5 EMDB-20998: Lipophilic Envelope-spanning Tunnel B (LetB), Map 6 EMDB-20999: Lipophilic Envelope-spanning Tunnel B (LetB), Map 7 EMDB-21000: Lipophilic Envelope-spanning Tunnel B (LetB), Map 8 PDB-6vci: |
化合物 | ChemComp-HOH: |
由来 |
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キーワード | LIPID TRANSPORT / bacterial cell envelope / MCE / YebT / conformational dynamics / LetB |