ジャーナル: Ultramicroscopy / 年: 2014 タイトル: CTER-rapid estimation of CTF parameters with error assessment. 著者: Pawel A Penczek / Jia Fang / Xueming Li / Yifan Cheng / Justus Loerke / Christian M T Spahn / 要旨: In structural electron microscopy, the accurate estimation of the Contrast Transfer Function (CTF) parameters, particularly defocus and astigmatism, is of utmost importance for both initial ...In structural electron microscopy, the accurate estimation of the Contrast Transfer Function (CTF) parameters, particularly defocus and astigmatism, is of utmost importance for both initial evaluation of micrograph quality and for subsequent structure determination. Due to increases in the rate of data collection on modern microscopes equipped with new generation cameras, it is also important that the CTF estimation can be done rapidly and with minimal user intervention. Finally, in order to minimize the necessity for manual screening of the micrographs by a user it is necessary to provide an assessment of the errors of fitted parameters values. In this work we introduce CTER, a CTF parameters estimation method distinguished by its computational efficiency. The efficiency of the method makes it suitable for high-throughput EM data collection, and enables the use of a statistical resampling technique, bootstrap, that yields standard deviations of estimated defocus and astigmatism amplitude and angle, thus facilitating the automation of the process of screening out inferior micrograph data. Furthermore, CTER also outputs the spatial frequency limit imposed by reciprocal space aliasing of the discrete form of the CTF and the finite window size. We demonstrate the efficiency and accuracy of CTER using a data set collected on a 300kV Tecnai Polara (FEI) using the K2 Summit DED camera in super-resolution counting mode. Using CTER we obtained a structure of the 80S ribosome whose large subunit had a resolution of 4.03Å without, and 3.85Å with, inclusion of astigmatism parameters.
ダウンロード / ファイル: emd_5889.map.gz / 形式: CCP4 / 大きさ: 81.8 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
human 80S ribosome
ボクセルのサイズ
X=Y=Z: 1.264 Å
密度
表面レベル
登録者による: 8.75 / ムービー #1: 8.75
最小 - 最大
-6.2626152 - 48.298103330000004
平均 (標準偏差)
0.60599691 (±2.57134986)
対称性
空間群: 1
詳細
EMDB XML:
マップ形状
Axis order
X
Y
Z
Origin
0
0
0
サイズ
280
280
280
Spacing
280
280
280
セル
A=B=C: 353.92 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
1.264
1.264
1.264
M x/y/z
280
280
280
origin x/y/z
0.000
0.000
0.000
length x/y/z
353.920
353.920
353.920
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
-95
-75
153
NX/NY/NZ
200
200
200
MAP C/R/S
1
2
3
start NC/NR/NS
0
0
0
NC/NR/NS
280
280
280
D min/max/mean
-6.263
48.298
0.606
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添付データ
-
試料の構成要素
-
全体 : human 80S ribosome
全体
名称: human 80S ribosome
要素
試料: human 80S ribosome
複合体: 80S ribosome
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超分子 #1000: human 80S ribosome
超分子
名称: human 80S ribosome / タイプ: sample / ID: 1000 / 詳細: sample was monodisperse / 集合状態: 1 / Number unique components: 1
分子量
理論値: 4.2 MDa
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超分子 #1: 80S ribosome
超分子
名称: 80S ribosome / タイプ: complex / ID: 1 / 組換発現: No / データベース: NCBI / Ribosome-details: ribosome-eukaryote: ALL
由来(天然)
生物種: Homo sapiens (ヒト) / 別称: human / 組織: kidney / 細胞: HEK293 / Organelle: cytosol
分子量
理論値: 4.2 MDa
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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
単粒子再構成法
試料の集合状態
particle
-
試料調製
緩衝液
pH: 7.5 詳細: 20 mM HEPES, pH 7.5, 100 mM KCl, 1.5 mM MgCl2, 0.5 mM spermidine, 0.04 mM spermine, 1 mM DTT
グリッド
詳細: Quantifoil 2/4 Cu/Re with custom continuous carbon film
凍結
凍結剤: ETHANE / 装置: OTHER
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電子顕微鏡法
顕微鏡
FEI TECNAI F30
日付
2013年2月12日
撮影
カテゴリ: CCD / フィルム・検出器のモデル: GATAN K2 (4k x 4k) / 実像数: 893 詳細: The data was collected in movie mode at 39,000x magnification. Frames 3 to 20 were decimated twice, motion corrected with UCSHImage4, and averaged.
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 / Cs: 2 mm
試料ステージ
試料ホルダーモデル: GATAN LIQUID NITROGEN
実験機器
モデル: Tecnai F30 / 画像提供: FEI Company
-
画像解析
CTF補正
詳細: Per-particle
最終 再構成
アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 3.85 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: SPARX 詳細: The resolution reported is for the large subunit (60S) only. 使用した粒子像数: 35198