ジャーナル: EMBO Rep / 年: 2017 タイトル: structure of the Dot/Icm type IV secretion system by electron cryotomography. 著者: Debnath Ghosal / Yi-Wei Chang / Kwangcheol C Jeong / Joseph P Vogel / Grant J Jensen / 要旨: Type IV secretion systems (T4SSs) are large macromolecular machines that translocate protein and DNA and are involved in the pathogenesis of multiple human diseases. Here, using electron ...Type IV secretion systems (T4SSs) are large macromolecular machines that translocate protein and DNA and are involved in the pathogenesis of multiple human diseases. Here, using electron cryotomography (ECT), we report the structure of the Dot/Icm type IVB secretion system (T4BSS) utilized by the human pathogen This is the first structure of a type IVB secretion system, and also the first structure of any T4SS While the Dot/Icm system shares almost no sequence similarity with type IVA secretion systems (T4ASSs), its overall structure is seen here to be remarkably similar to previously reported T4ASS structures (those encoded by the R388 plasmid in and the cag pathogenicity island in ). This structural similarity suggests shared aspects of mechanism. However, compared to the negative-stain reconstruction of the purified T4ASS from the R388 plasmid, the Dot/Icm system is approximately twice as long and wide and exhibits several additional large densities, reflecting type-specific elaborations and potentially better structural preservation .
A: 839.99994 Å / B: 1007.99994 Å / C: 839.99994 Å α=β=γ: 90.0 °
CCP4マップ ヘッダ情報:
mode
Image stored as Reals
Å/pix. X/Y/Z
8.4
8.4
8.4
M x/y/z
100
120
100
origin x/y/z
0.000
0.000
0.000
length x/y/z
840.000
1008.000
840.000
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
0
0
0
NX/NY/NZ
28
11
56
MAP C/R/S
1
2
3
start NC/NR/NS
0
0
0
NC/NR/NS
100
120
100
D min/max/mean
0.000
1.000
0.352
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添付データ
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試料の構成要素
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全体 : Legionella pneumophila Dot/Icm type IVB secretion system core complex
全体
名称: Legionella pneumophila Dot/Icm type IVB secretion system core complex
要素
複合体: Legionella pneumophila Dot/Icm type IVB secretion system core complex
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超分子 #1: Legionella pneumophila Dot/Icm type IVB secretion system core complex
超分子
名称: Legionella pneumophila Dot/Icm type IVB secretion system core complex タイプ: complex / ID: 1 / 親要素: 0 詳細: We used electron cryotomography and subtomogram averaging to visualize L. pneumophila Dot/Icm core complex directly in intact, frozen-hydrated bacteria cells.
由来(天然)
生物種: Legionella pneumophila (バクテリア) / 株: Lp02
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実験情報
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構造解析
手法
クライオ電子顕微鏡法
解析
サブトモグラム平均法
試料の集合状態
cell
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試料調製
緩衝液
pH: 6.9
凍結
凍結剤: ETHANE-PROPANE
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
撮影
フィルム・検出器のモデル: GATAN K2 SUMMIT (4k x 4k) 平均電子線量: 1.2 e/Å2
電子線
加速電圧: 300 kV / 電子線源: FIELD EMISSION GUN
電子光学系
照射モード: FLOOD BEAM / 撮影モード: BRIGHT FIELD
実験機器
モデル: Titan Krios / 画像提供: FEI Company
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画像解析
最終 再構成
想定した対称性 - 点群: C2 (2回回転対称) / 解像度のタイプ: BY AUTHOR / 解像度: 30.0 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: IMOD, TOMO3D / 詳細: RESMAP / 使用したサブトモグラム数: 261