9CPK

D8 symmetry reconstruction of MmCPn in closed state

Summary for 9CPK

• Entry DOI: 10.2210/pdb9cpk/pdb
• EMDB information: 45793
• Descriptor: Chaperonin, MAGNESIUM ION, ADENOSINE-5'-DIPHOSPHATE, ... (6 entities in total)
• Functional Keywords: archaea chaperonin in closed state with atp/alfx, chaperone
• Biological source: Methanococcus maripaludis
• Total number of polymer chains: 16
• Total formula weight: 941837.49

Authors

Yanyan, Z. (deposition date: 2024-07-18, release date: 2025-07-30, Last modification date: 2025-10-08)

Primary citation

Zhao, Y.,Schmid, M.F.,Chiu, W.
Cost-benefit analysis of cryogenic electron tomography subtomogram averaging of chaperonin MmCpn at near atomic resolution.
Structure, 33:372-380.e2, 2025

PubMed Abstract: Cryogenic electron microscopy single particle analysis (cryoEM-SPA) has evolved into a routine approach for determining macromolecule structures to near-atomic resolution. Cryogenic electron tomography subtomogram averaging (cryoET-STA) toward a similar resolution, in contrast, is still under active development. Here, we use the archeal chaperonin MmCpn as a model macromolecule to quantitatively investigate the resolution limiting factors of cryoET-STA in terms of cumulative electron dose, ice thickness, subtomogram numbers, and tilt angle ranges. By delineating the feasibility and experimental factors of attaining near atomic resolution structure with cryoET-STA, especially the effect of electron damage through the tilt series and inelastic scattering at various ice thickness, we encourage a customized tilt series collection strategy for efficient throughput. This study provides a biophysical basis for the application of cryoET-STA (for highly symmetric molecules like MmCpn) toward high resolution and the rationales in using cryoET-STA to achieve an efficient outcome at the desired resolution.

PubMed: 39644888
DOI: 10.1016/j.str.2024.11.008

Experimental method

ELECTRON MICROSCOPY (2.56 Å)