PDBsum entry 3j9i

Hydrolase

PDB id: 3j9i

Contents

Protein chains

(+ 8 more) 224 a.a.

(+ 8 more) 203 a.a.

PDB id:

3j9i

Name:

Hydrolase

Title:

Thermoplasma acidophilum 20s proteasome

Structure:

Proteasome subunit alpha. Chain: s, f, t, g, u, a, o, b, p, c, q, d, r, e. Synonym: 20s proteasome alpha subunit, proteasome core protein psma. Engineered: yes. Proteasome subunit beta. Chain: z, m, 1, n, 2, h, v, i, w, j, x, k, y, l. Synonym: 20s proteasome beta subunit, proteasome core protein psmb. Engineered: yes

Source:

Thermoplasma acidophilum. Organism_taxid: 2303. Gene: psma, ta1288. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: psmb, ta0612. Expression_system_taxid: 562

Authors:

X.Li,P.Mooney,S.Zheng,C.Booth,M.B.Braunfeld,S.Gubbens,D.A.Agard, Y.Cheng

Key ref:

X.Li et al. (2013). Electron counting and beam-induced motion correction enable near-atomic-resolution single-particle cryo-EM. Nat Methods, 10, 584-590. PubMed id: 23644547 DOI: 10.1038/nmeth.2472

Date:

02-Feb-15 Release date: 18-Feb-15

Protein chains

P25156  (PSA_THEAC) -  Proteasome subunit alpha from Thermoplasma acidophilum (strain ATCC 25905 / DSM 1728 / JCM 9062 / NBRC 15155 / AMRC-C165)

Seq: 233 a.a.

Struc: 224 a.a.

Protein chains

P28061  (PSB_THEAC) -  Proteasome subunit beta from Thermoplasma acidophilum (strain ATCC 25905 / DSM 1728 / JCM 9062 / NBRC 15155 / AMRC-C165)

Seq: 211 a.a.

Struc: 203 a.a.

Enzyme reactions

• Enzyme class: Chains S, Z, F, M, T, 1, G, N, U, 2, A, H, O, V, B, I, P, W, C, J, Q, X, D, K, R, Y, E, L: E.C.3.4.25.1 - proteasome endopeptidase complex.
• Reaction: Cleavage at peptide bonds with very broad specificity.

DOI no: 10.1038/nmeth.2472

Nat Methods 10:584-590 (2013)

PubMed id: 23644547

Electron counting and beam-induced motion correction enable near-atomic-resolution single-particle cryo-EM.

X.Li, P.Mooney, S.Zheng, C.R.Booth, M.B.Braunfeld, S.Gubbens, D.A.Agard, Y.Cheng.

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.