7SWC

MicroED structure of proteinase K from a 550 nm thick lamella measured at 300 kV

7SWC の概要

• エントリーDOI: 10.2210/pdb7swc/pdb
• EMDBエントリー: 25470
• 分子名称: Proteinase K (1 entity in total)
• 機能のキーワード: serine protease, hydrolase
• 由来する生物種: Parengyodontium album (Engyodontium album, Tritirachium album)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28930.78

構造登録者

Martynowycz, M.W.,Clabbers, M.T.B.,Unge, J.,Hattne, J.,Gonen, T. (登録日: 2021-11-19, 公開日: 2022-09-07, 最終更新日: 2024-10-16)

主引用文献

Martynowycz, M.W.,Clabbers, M.T.B.,Unge, J.,Hattne, J.,Gonen, T.
Benchmarking the ideal sample thickness in cryo-EM.
Proc.Natl.Acad.Sci.USA, 118:-, 2021

PubMed Abstract: The relationship between sample thickness and quality of data obtained is investigated by microcrystal electron diffraction (MicroED). Several electron microscopy (EM) grids containing proteinase K microcrystals of similar sizes from the same crystallization batch were prepared. Each grid was transferred into a focused ion beam and a scanning electron microscope in which the crystals were then systematically thinned into lamellae between 95- and 1,650-nm thick. MicroED data were collected at either 120-, 200-, or 300-kV accelerating voltages. Lamellae thicknesses were expressed in multiples of the corresponding inelastic mean free path to allow the results from different acceleration voltages to be compared. The quality of the data and subsequently determined structures were assessed using standard crystallographic measures. Structures were reliably determined with similar quality from crystalline lamellae up to twice the inelastic mean free path. Lower resolution diffraction was observed at three times the mean free path for all three accelerating voltages, but the data quality was insufficient to yield structures. Finally, no coherent diffraction was observed from lamellae thicker than four times the calculated inelastic mean free path. This study benchmarks the ideal specimen thickness with implications for all cryo-EM methods.

PubMed: 34873060
DOI: 10.1073/pnas.2108884118

実験手法

ELECTRON CRYSTALLOGRAPHY (2.9 Å)