3QDR

Structural characterization of the interaction of colicin A, colicin N, and TolB with the TolAIII translocon

3QDR の概要

• エントリーDOI: 10.2210/pdb3qdr/pdb
• 関連するPDBエントリー: 3QDP
• 分子名称: Protein tolA, Colicin-A, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL, ... (4 entities in total)
• 機能のキーワード: cola, tola, complex, translocation, cola binds to tola, methylation, protein transport-toxin complex, protein transport/toxin
• 由来する生物種: Escherichia coli; 詳細
• 細胞内の位置: Cell inner membrane; Single-pass type II membrane protein: P19934; Cell membrane; Multi-pass membrane protein (Potential): P04480
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 20066.51

構造登録者

Li, C. (登録日: 2011-01-19, 公開日: 2012-01-25, 最終更新日: 2012-06-20)

主引用文献

Li, C.,Zhang, Y.,Vankemmelbeke, M.,Hecht, O.,Aleanizy, F.S.,Macdonald, C.,Moore, G.R.,James, R.,Penfold, C.N.
Structural Evidence That Colicin A Protein Binds to a Novel Binding Site of TolA Protein in Escherichia coli Periplasm.
J.Biol.Chem., 287:19048-19057, 2012

PubMed Abstract: The Tol assembly of proteins is an interacting network of proteins located in the Escherichia coli cell envelope that transduces energy and contributes to cell integrity. TolA is central to this network linking the inner and outer membranes by interactions with TolQ, TolR, TolB, and Pal. Group A colicins, such as ColA, parasitize the Tol network through interactions with TolA and/or TolB to facilitate translocation through the cell envelope to reach their cytotoxic site of action. We have determined the first structure of the C-terminal domain of TolA (TolAIII) bound to an N-terminal ColA polypeptide (TA(53-107)). The interface region of the TA(53-107)-TolAIII complex consists of polar contacts linking residues Arg-92 to Arg-96 of ColA with residues Leu-375-Pro-380 of TolA, which constitutes a β-strand addition commonly seen in more promiscuous protein-protein contacts. The interface region also includes three cation-π interactions (Tyr-58-Lys-368, Tyr-90-Lys-379, Phe-94-Lys-396), which have not been observed in any other colicin-Tol protein complex. Mutagenesis of the interface residues of ColA or TolA revealed that the effect on the interaction was cumulative; single mutations of either partner had no effect on ColA activity, whereas mutations of three or more residues significantly reduced ColA activity. Mutagenesis of the aromatic ring component of the cation-π interacting residues showed Tyr-58 of ColA to be essential for the stability of complex formation. TA(53-107) binds on the opposite side of TolAIII to that used by g3p, ColN, or TolB, illustrating the flexible nature of TolA as a periplasmic hub protein.

PubMed: 22493500
DOI: 10.1074/jbc.M112.342246

実験手法

X-RAY DIFFRACTION (2.65 Å)