ジャーナル: Nature / 年: 2014 タイトル: Structure of a type IV secretion system. 著者: Harry H Low / Francesca Gubellini / Angel Rivera-Calzada / Nathalie Braun / Sarah Connery / Annick Dujeancourt / Fang Lu / Adam Redzej / Rémi Fronzes / Elena V Orlova / Gabriel Waksman / 要旨: Bacterial type IV secretion systems translocate virulence factors into eukaryotic cells, distribute genetic material between bacteria and have shown potential as a tool for the genetic modification ...Bacterial type IV secretion systems translocate virulence factors into eukaryotic cells, distribute genetic material between bacteria and have shown potential as a tool for the genetic modification of human cells. Given the complex choreography of the substrate through the secretion apparatus, the molecular mechanism of the type IV secretion system has proved difficult to dissect in the absence of structural data for the entire machinery. Here we use electron microscopy to reconstruct the type IV secretion system encoded by the Escherichia coli R388 conjugative plasmid. We show that eight proteins assemble in an intricate stoichiometric relationship to form an approximately 3 megadalton nanomachine that spans the entire cell envelope. The structure comprises an outer membrane-associated core complex connected by a central stalk to a substantial inner membrane complex that is dominated by a battery of 12 VirB4 ATPase subunits organized as side-by-side hexameric barrels. Our results show a secretion system with markedly different architecture, and consequently mechanism, to other known bacterial secretion systems.
全体 : Structure of a bacterial Type IV secretion system from Escherichi...
全体
名称: Structure of a bacterial Type IV secretion system from Escherichia coli R388 conjugative plasmid
要素
試料: Structure of a bacterial Type IV secretion system from Escherichia coli R388 conjugative plasmid
タンパク質・ペプチド: Type IV secretion system from R388 conjugative plasmid
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超分子 #1000: Structure of a bacterial Type IV secretion system from Escherichi...
超分子
名称: Structure of a bacterial Type IV secretion system from Escherichia coli R388 conjugative plasmid タイプ: sample / ID: 1000 / Number unique components: 1
分子量
実験値: 3 MDa / 理論値: 3.4 MDa 手法: Calculation based on stoichiometry determination of individual components within the complex
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分子 #1: Type IV secretion system from R388 conjugative plasmid
分子
名称: Type IV secretion system from R388 conjugative plasmid タイプ: protein_or_peptide / ID: 1 / 組換発現: Yes