3J9I

Thermoplasma acidophilum 20S proteasome

Summary for 3J9I

• Entry DOI: 10.2210/pdb3j9i/pdb
• Related: 1PMA
• EMDB information: 5623
• Descriptor: Proteasome subunit alpha, Proteasome subunit beta (2 entities in total)
• Functional Keywords: proteasome, hydrolase
• Biological source: Thermoplasma acidophilum; More
• Total number of polymer chains: 28
• Total formula weight: 658995.81

Authors

Li, X.,Mooney, P.,Zheng, S.,Booth, C.,Braunfeld, M.B.,Gubbens, S.,Agard, D.A.,Cheng, Y. (deposition date: 2015-02-02, release date: 2015-02-18, Last modification date: 2024-02-21)

Primary citation

Li, X.,Mooney, P.,Zheng, S.,Booth, C.R.,Braunfeld, M.B.,Gubbens, S.,Agard, D.A.,Cheng, Y.
Electron counting and beam-induced motion correction enable near-atomic-resolution single-particle cryo-EM.
Nat.Methods, 10:584-590, 2013

PubMed Abstract: In recent work with large high-symmetry viruses, single-particle electron cryomicroscopy (cryo-EM) has achieved the determination of near-atomic-resolution structures by allowing direct fitting of atomic models into experimental density maps. However, achieving this goal with smaller particles of lower symmetry remains challenging. Using a newly developed single electron-counting detector, we confirmed that electron beam-induced motion substantially degrades resolution, and we showed that the combination of rapid readout and nearly noiseless electron counting allow image blurring to be corrected to subpixel accuracy, restoring intrinsic image information to high resolution (Thon rings visible to ∼3 Å). Using this approach, we determined a 3.3-Å-resolution structure of an ∼700-kDa protein with D7 symmetry, the Thermoplasma acidophilum 20S proteasome, showing clear side-chain density. Our method greatly enhances image quality and data acquisition efficiency-key bottlenecks in applying near-atomic-resolution cryo-EM to a broad range of protein samples.

PubMed: 23644547
DOI: 10.1038/nmeth.2472

Experimental method

ELECTRON MICROSCOPY (3.3 Å)