ジャーナル: Nat Microbiol / 年: 2022 タイトル: Identification and structure of an extracellular contractile injection system from the marine bacterium Algoriphagus machipongonensis. 著者: Jingwei Xu / Charles F Ericson / Yun-Wei Lien / Florentine U N Rutaganira / Fabian Eisenstein / Miki Feldmüller / Nicole King / Martin Pilhofer / 要旨: Contractile injection systems (CISs) are phage tail-like nanomachines, mediating bacterial cell-cell interactions as either type VI secretion systems (T6SSs) or extracellular CISs (eCISs). ...Contractile injection systems (CISs) are phage tail-like nanomachines, mediating bacterial cell-cell interactions as either type VI secretion systems (T6SSs) or extracellular CISs (eCISs). Bioinformatic studies uncovered a phylogenetic group of hundreds of putative CIS gene clusters that are highly diverse and widespread; however, only four systems have been characterized. Here we studied a putative CIS gene cluster in the marine bacterium Algoriphagus machipongonensis. Using an integrative approach, we show that the system is compatible with an eCIS mode of action. Our cryo-electron microscopy structure revealed several features that differ from those seen in other CISs: a 'cap adaptor' located at the distal end, a 'plug' exposed to the tube lumen, and a 'cage' formed by massive extensions of the baseplate. These elements are conserved in other CISs, and our genetic tools identified that they are required for assembly, cargo loading and function. Furthermore, our atomic model highlights specific evolutionary hotspots and will serve as a framework for understanding and re-engineering CISs.
A: 10997.76 Å / B: 15465.6 Å / C: 4296.0 Å α=β=γ: 90.0 °
CCP4マップ ヘッダ情報:
mode
Image stored as Integer*27
Å/pix. X/Y/Z
10.74
10.74
10.74
M x/y/z
1024
1440
400
origin x/y/z
0.000
0.000
0.000
length x/y/z
10997.760
15465.600
4296.000
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
0
0
0
NX/NY/NZ
450
450
450
MAP C/R/S
1
2
3
start NC/NR/NS
-208
209
200
NC/NR/NS
1024
1440
400
D min/max/mean
-418.000
261.000
2.274
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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 : The purified extracellular contractile injection system (AlgoCIS)...
全体
名称: The purified extracellular contractile injection system (AlgoCIS) wild-type
要素
複合体: The purified extracellular contractile injection system (AlgoCIS) wild-type
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超分子 #1: The purified extracellular contractile injection system (AlgoCIS)...
超分子
名称: The purified extracellular contractile injection system (AlgoCIS) wild-type タイプ: complex / ID: 1 / 親要素: 0
由来(天然)
生物種: Algoriphagus machipongonensis (バクテリア)
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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
電子線トモグラフィー法
試料の集合状態
particle
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試料調製
緩衝液
pH: 7.5
凍結
凍結剤: ETHANE-PROPANE
切片作成
その他: NO SECTIONING
位置合わせマーカー
Manufacturer: cytodiagnostics / 直径: 10 nm
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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 K3 (6k x 4k) / 検出モード: COUNTING / 平均電子線量: 2.1 e/Å2 詳細: 2.1 electrons for each tilt, while total ~130 electron for one tilt series (61 tilts).