ジャーナル: Nat Commun / 年: 2016 タイトル: Structure of the poly-C9 component of the complement membrane attack complex. 著者: Natalya V Dudkina / Bradley A Spicer / Cyril F Reboul / Paul J Conroy / Natalya Lukoyanova / Hans Elmlund / Ruby H P Law / Susan M Ekkel / Stephanie C Kondos / Robert J A Goode / Georg Ramm / ...著者: Natalya V Dudkina / Bradley A Spicer / Cyril F Reboul / Paul J Conroy / Natalya Lukoyanova / Hans Elmlund / Ruby H P Law / Susan M Ekkel / Stephanie C Kondos / Robert J A Goode / Georg Ramm / James C Whisstock / Helen R Saibil / Michelle A Dunstone / 要旨: The membrane attack complex (MAC)/perforin-like protein complement component 9 (C9) is the major component of the MAC, a multi-protein complex that forms pores in the membrane of target pathogens. In ...The membrane attack complex (MAC)/perforin-like protein complement component 9 (C9) is the major component of the MAC, a multi-protein complex that forms pores in the membrane of target pathogens. In contrast to homologous proteins such as perforin and the cholesterol-dependent cytolysins (CDCs), all of which require the membrane for oligomerisation, C9 assembles directly onto the nascent MAC from solution. However, the molecular mechanism of MAC assembly remains to be understood. Here we present the 8 Å cryo-EM structure of a soluble form of the poly-C9 component of the MAC. These data reveal a 22-fold symmetrical arrangement of C9 molecules that yield an 88-strand pore-forming β-barrel. The N-terminal thrombospondin-1 (TSP1) domain forms an unexpectedly extensive part of the oligomerisation interface, thus likely facilitating solution-based assembly. These TSP1 interactions may also explain how additional C9 subunits can be recruited to the growing MAC subsequent to membrane insertion.
モード: BRIGHT FIELD / 倍率(公称値): 77000 X / 倍率(補正後): 36232 X / 最大 デフォーカス(公称値): 4000 nm / 最小 デフォーカス(公称値): 1500 nm / Cs: 2.3 mm
試料ホルダ
温度: 85 K
撮影
電子線照射量: 25 e/Å2 フィルム・検出器のモデル: GATAN K2 SUMMIT (4k x 4k)
画像スキャン
デジタル画像の数: 1385
-
解析
EMソフトウェア
ID
名称
バージョン
カテゴリ
1
CTFFIND
3
CTF補正
2
IMAGIC
3次元再構成
3
RELION
3次元再構成
CTF補正
詳細: EACH MICROGRAPH
対称性
点対称性: C22 (22回回転対称)
3次元再構成
解像度: 6.7 Å / 粒子像の数: 5000 / ピクセルサイズ(公称値): 2.76 Å / ピクセルサイズ(実測値): 2.76 Å 詳細: SUBMISSION BASED ON EXPERIMENTAL DATA FROM EMDB EMD-3235. (DEPOSITION ID: 13993). 対称性のタイプ: POINT