ジャーナル: J Biol Chem / 年: 2016 タイトル: Topology and Structure/Function Correlation of Ring- and Gate-forming Domains in the Dynamic Secretin Complex of Thermus thermophilus. 著者: Ralf Salzer / Edoardo D'Imprima / Vicki A M Gold / Ilona Rose / Moritz Drechsler / Janet Vonck / Beate Averhoff / 要旨: Secretins are versatile outer membrane pores used by many bacteria to secrete proteins, toxins, or filamentous phages; extrude type IV pili (T4P); or take up DNA. Extrusion of T4P and natural ...Secretins are versatile outer membrane pores used by many bacteria to secrete proteins, toxins, or filamentous phages; extrude type IV pili (T4P); or take up DNA. Extrusion of T4P and natural transformation of DNA in the thermophilic bacterium Thermus thermophilus requires a unique secretin complex comprising six stacked rings, a membrane-embedded cone structure, and two gates that open and close a central channel. To investigate the role of distinct domains in ring and gate formation, we examined a set of deletion derivatives by cryomicroscopy techniques. Here we report that maintaining the N0 ring in the deletion derivatives led to stable PilQ complexes. Analyses of the variants unraveled that an N-terminal domain comprising a unique βββαβ fold is essential for the formation of gate 2. Furthermore, we identified four βαββα domains essential for the formation of the N2 to N5 rings. Mutant studies revealed that deletion of individual ring domains significantly reduces piliation. The N1, N2, N4, and N5 deletion mutants were significantly impaired in T4P-mediated twitching motility, whereas the motility of the N3 mutant was comparable with that of wild-type cells. This indicates that the deletion of the N3 ring leads to increased pilus dynamics, thereby compensating for the reduced number of pili of the N3 mutant. All mutants exhibit a wild-type natural transformation phenotype, leading to the conclusion that DNA uptake is independent of functional T4P.
ダウンロード / ファイル: emd_8224.map.gz / 形式: CCP4 / 大きさ: 501 KB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
None
ボクセルのサイズ
X=Y=Z: 11.56 Å
密度
表面レベル
登録者による: 158. / ムービー #1: 158
最小 - 最大
151. - 163.999979999999994
平均 (標準偏差)
157.50030000000001 (±0.7866444)
対称性
空間群: 1
詳細
EMDB XML:
マップ形状
Axis order
X
Y
Z
Origin
-13
-13
-17
サイズ
40
40
80
Spacing
40
40
80
セル
A: 462.40002 Å / B: 462.40002 Å / C: 924.80005 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
11.56
11.56
11.56
M x/y/z
40
40
80
origin x/y/z
0.000
0.000
0.000
length x/y/z
462.400
462.400
924.800
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
0
0
-41
NX/NY/NZ
73
73
84
MAP C/R/S
1
2
3
start NC/NR/NS
-13
-13
-17
NC/NR/NS
40
40
80
D min/max/mean
151.000
164.000
157.500
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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 : Structure of a mutant type IV pilus machinery (delta N1 ring dele...
全体
名称: Structure of a mutant type IV pilus machinery (delta N1 ring deletion in PilQ) in the closed state from Thermus thermophilus
要素
複合体: Structure of a mutant type IV pilus machinery (delta N1 ring deletion in PilQ) in the closed state from Thermus thermophilus
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超分子 #1: Structure of a mutant type IV pilus machinery (delta N1 ring dele...
超分子
名称: Structure of a mutant type IV pilus machinery (delta N1 ring deletion in PilQ) in the closed state from Thermus thermophilus タイプ: complex / ID: 1 / 親要素: 0
由来(天然)
生物種: Thermus thermophilus (バクテリア) / 株: HB27
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実験情報
-
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
-
試料調製
緩衝液
pH: 7.4 / 構成要素:
濃度
名称
20.0 mM
Tris
100.0 mM
EDTA
グリッド
モデル: Quantifoil R2/2 / 材質: COPPER / メッシュ: 300
凍結
凍結剤: ETHANE / チャンバー内湿度: 20 % / 装置: HOMEMADE PLUNGER 詳細: Cell solutions were mixed 1:1 (v/v) with 10 nm ProteinA-gold particles. 3 microlitres of sample were applied to grids and blotted on one side for ~5s before plunging.
詳細
Cellular suspension
-
電子顕微鏡法
顕微鏡
JEOL 3200FSC
特殊光学系
エネルギーフィルター - 名称: In-column Omega Filter
撮影
フィルム・検出器のモデル: GATAN K2 SUMMIT (4k x 4k) 検出モード: COUNTING / 平均電子線量: 3.0 e/Å2 詳細: Each image in every tilt series is a drift corrected sum of 3-5 frames
想定した対称性 - 点群: C12 (12回回転対称) / アルゴリズム: BACK PROJECTION / 解像度のタイプ: BY AUTHOR / 解像度: 50.0 Å / 解像度の算出法: FSC 0.5 CUT-OFF 詳細: Resolution estimate was calculated using a mask to exclude the membrane and peptidoglycan. C12 symmetry was applied to the masked central PilQ core by rotation of each subvolume by 30 degrees ...詳細: Resolution estimate was calculated using a mask to exclude the membrane and peptidoglycan. C12 symmetry was applied to the masked central PilQ core by rotation of each subvolume by 30 degrees (360 degrees/12) prior to alignment search. 使用したサブトモグラム数: 432