ジャーナル: Nat Microbiol / 年: 2022 タイトル: Structure of a thylakoid-anchored contractile injection system in multicellular cyanobacteria. 著者: Gregor L Weiss / Fabian Eisenstein / Ann-Katrin Kieninger / Jingwei Xu / Hannah A Minas / Milena Gerber / Miki Feldmüller / Iris Maldener / Karl Forchhammer / Martin Pilhofer / 要旨: Contractile injection systems (CISs) mediate cell-cell interactions by phage tail-like structures, using two distinct modes of action: extracellular CISs are released into the medium, while type 6 ...Contractile injection systems (CISs) mediate cell-cell interactions by phage tail-like structures, using two distinct modes of action: extracellular CISs are released into the medium, while type 6 secretion systems (T6SSs) are attached to the cytoplasmic membrane and function upon cell-cell contact. Here, we characterized a CIS in the multicellular cyanobacterium Anabaena, with features distinct from extracellular CISs and T6SSs. Cryo-electron tomography of focused ion beam-milled cells revealed that CISs were anchored in thylakoid membrane stacks, facing the cell periphery. Single particle cryo-electron microscopy showed that this unique in situ localization was mediated by extensions of tail fibre and baseplate components. On stress, cyanobacteria induced the formation of ghost cells, presenting thylakoid-anchored CISs to the environment. Functional assays suggest that these CISs may mediate ghost cell formation and/or interactions of ghost cells with other organisms. Collectively, these data provide a framework for understanding the evolutionary re-engineering of CISs and potential roles of these CISs in cyanobacterial programmed cell death.
ダウンロード / ファイル: emd_13770.map.gz / 形式: CCP4 / 大きさ: 322.9 MB / タイプ: IMAGE STORED AS SIGNED BYTE
注釈
Cryo-electron tomogram of cryo-FIB milled Anabaena PCC7120 revealed thylakoid-anchored contractile injection systems
ボクセルのサイズ
X=Y=Z: 13.51 Å
密度
最小 - 最大
-128.0 - 127.0
平均 (標準偏差)
-3.4305289 (±24.041536000000001)
対称性
空間群: 1
詳細
EMDB XML:
マップ形状
Axis order
X
Y
Z
Origin
16
-16
-190
サイズ
928
960
380
Spacing
960
928
380
セル
A: 12969.601 Å / B: 12537.28 Å / C: 5133.8003 Å α=β=γ: 90.0 °
CCP4マップ ヘッダ情報:
mode
envelope stored as signed bytes (from -128 lowest to 127 highest)
Å/pix. X/Y/Z
13.510001041667
13.51
13.51
M x/y/z
960
928
380
origin x/y/z
0.000
0.000
0.000
length x/y/z
12969.601
12537.280
5133.800
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
0
0
0
NX/NY/NZ
360
360
360
MAP C/R/S
1
2
3
start NC/NR/NS
-16
16
-190
NC/NR/NS
960
928
380
D min/max/mean
-128.000
127.000
-3.431
-
添付データ
-
試料の構成要素
-
全体 : Septal region of a cryo-FIB milled Anabaena PCC 7120 filament
全体
名称: Septal region of a cryo-FIB milled Anabaena PCC 7120 filament
要素
細胞: Septal region of a cryo-FIB milled Anabaena PCC 7120 filament
-
超分子 #1: Septal region of a cryo-FIB milled Anabaena PCC 7120 filament
超分子
名称: Septal region of a cryo-FIB milled Anabaena PCC 7120 filament タイプ: cell / ID: 1 / 親要素: 0 詳細: Several thylakoid membrane-anchored contractile injection systems are visible
由来(天然)
生物種: Nostoc sp. PCC 7120 = FACHB-418 (バクテリア)
-
実験情報
-
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
cell
-
試料調製
緩衝液
pH: 7.4
凍結
凍結剤: ETHANE-PROPANE
切片作成
集束イオンビーム - 装置: OTHER / 集束イオンビーム - イオン: OTHER / 集束イオンビーム - 電圧: 30 / 集束イオンビーム - 電流: 0.024 / 集束イオンビーム - 時間: 1800 / 集束イオンビーム - 温度: 128 K / 集束イオンビーム - Initial thickness: 3000 / 集束イオンビーム - 最終 厚さ: 200 集束イオンビーム - 詳細: The value given for _em_focused_ion_beam.instrument is TFS Helios NanoLab 600i. This is not in a list of allowed values {'DB235', 'OTHER'} so OTHER is written into the XML file.
-
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 QUANTUM (4k x 4k) 平均電子線量: 2.3 e/Å2