7KNS

Cryo-EM structure of jack bean urease

Summary for 7KNS

• Entry DOI: 10.2210/pdb7kns/pdb
• EMDB information: 20016
• Descriptor: Urease, NICKEL (II) ION, PHOSPHATE ION (3 entities in total)
• Functional Keywords: urease, hydrolase
• Biological source: Canavalia ensiformis (Jack bean)
• Total number of polymer chains: 6
• Total formula weight: 546337.73

Authors

Feathers, J.R.,Spoth, K.A.,Fromme, J.C. (deposition date: 2020-11-05, release date: 2021-03-24, Last modification date: 2025-04-02)

Primary citation

Feathers, J.R.,Spoth, K.A.,Fromme, J.C.
Experimental evaluation of super-resolution imaging and magnification choice in single-particle cryo-EM.
J Struct Biol X, 5:100047-100047, 2021

PubMed Abstract: The resolution of cryo-EM reconstructions is fundamentally limited by the Nyquist frequency, which is half the sampling frequency of the detector and depends upon the magnification used. In principle, super-resolution imaging should enable reconstructions to surpass the physical Nyquist limit by increasing sampling frequency, yet there are few reports of reconstructions that do so. Here we directly examine the contribution of super-resolution information, obtained with the K3 direct electron detector using a 2-condenser microscope, to single-particle cryo-EM reconstructions surpassing the physical Nyquist limit. We also present a comparative analysis of a sample imaged at four different magnifications. This analysis demonstrates that lower magnifications can be beneficial, despite the loss of higher resolution signal, due to the increased number of particle images obtained. To highlight the potential utility of lower magnification data collection, we produced a 3.5 Å reconstruction of jack bean urease with particles from a single micrograph.

PubMed: 33817625
DOI: 10.1016/j.yjsbx.2021.100047

Experimental method

ELECTRON MICROSCOPY (2.77 Å)