6IAX

MloK1 model from single particle analysis of 2D crystals, class 1 (extended conformation)

Summary for 6IAX

• Entry DOI: 10.2210/pdb6iax/pdb
• Related: 6I9D 6QCY 6QCZ 6QD0 6QD1 6QD2 6QD3 6QD4
• EMDB information: 4441
• Descriptor: Cyclic nucleotide-gated potassium channel mll3241, POTASSIUM ION (2 entities in total)
• Functional Keywords: voltage-gated potassium channel, cyclic nucleotide-binding domain, ion channel, ion transport, membrane protein
• Biological source: Mesorhizobium japonicum (strain LMG 29417 / CECT 9101 / MAFF 303099) (Mesorhizobium loti (strain MAFF 303099))
• Total number of polymer chains: 4
• Total formula weight: 151143.38

Authors

Righetto, R.,Biyani, N.,Kowal, J.,Chami, M.,Stahlberg, H. (deposition date: 2018-11-27, release date: 2019-04-24, Last modification date: 2024-05-15)

Primary citation

Righetto, R.D.,Biyani, N.,Kowal, J.,Chami, M.,Stahlberg, H.
Retrieving high-resolution information from disordered 2D crystals by single-particle cryo-EM.
Nat Commun, 10:1722-1722, 2019

PubMed Abstract: Electron crystallography can reveal the structure of membrane proteins within 2D crystals under close-to-native conditions. High-resolution structural information can only be reached if crystals are perfectly flat and highly ordered. In practice, such crystals are difficult to obtain. Available image unbending algorithms correct for disorder, but only perform well on images of non-tilted, flat crystals, while out-of-plane distortions are not addressed. Here, we present an approach that employs single-particle refinement procedures to locally unbend crystals in 3D. With this method, density maps of the MloK1 potassium channel with a resolution of 4 Å were obtained from images of 2D crystals that do not diffract beyond 10 Å. Furthermore, 3D classification allowed multiple structures to be resolved, revealing a series of MloK1 conformations within a single 2D crystal. This conformational heterogeneity explains the poor diffraction observed and is related to channel function. The approach is implemented in the FOCUS package.

PubMed: 30979902
DOI: 10.1038/s41467-019-09661-5

Experimental method

ELECTRON MICROSCOPY (5.2 Å)