6KLO

Complex structure of Iota toxin enzymatic component (Ia) and binding component (Ib) pore with short stem

6KLO の概要

• エントリーDOI: 10.2210/pdb6klo/pdb
• EMDBエントリー: 0713
• 分子名称: Iota toxin component Ib, Iota toxin component Ia, CALCIUM ION (3 entities in total)
• 機能のキーワード: bacterial binary toxin, protein translocation channel, toxin
• 由来する生物種: Clostridium perfringens; 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 569274.82

構造登録者

Yoshida, T.,Yamada, T.,Kawamoto, A.,Mitsuoka, K.,Iwasaki, K.,Tsuge, H. (登録日: 2019-07-30, 公開日: 2020-01-15, 最終更新日: 2024-03-27)

主引用文献

Yamada, T.,Yoshida, T.,Kawamoto, A.,Mitsuoka, K.,Iwasaki, K.,Tsuge, H.
Cryo-EM structures reveal translocational unfolding in the clostridial binary iota toxin complex.
Nat.Struct.Mol.Biol., 27:288-296, 2020

PubMed Abstract: The iota toxin produced by Clostridium perfringens type E is a binary toxin comprising two independent polypeptides: Ia, an ADP-ribosyltransferase, and Ib, which is involved in cell binding and translocation of Ia across the cell membrane. Here we report cryo-EM structures of the translocation channel Ib-pore and its complex with Ia. The high-resolution Ib-pore structure demonstrates a similar structural framework to that of the catalytic ϕ-clamp of the anthrax protective antigen pore. However, the Ia-bound Ib-pore structure shows a unique binding mode of Ia: one Ia binds to the Ib-pore, and the Ia amino-terminal domain forms multiple weak interactions with two additional Ib-pore constriction sites. Furthermore, Ib-binding induces tilting and partial unfolding of the Ia N-terminal α-helix, permitting its extension to the ϕ-clamp gate. This new mechanism of N-terminal unfolding is crucial for protein translocation.

PubMed: 32123390
DOI: 10.1038/s41594-020-0388-6

実験手法

ELECTRON MICROSCOPY (2.8 Å)