6NBD

Human methemoglobin state 2 determined using single-particle cryo-EM at 200 keV

Summary for 6NBD

• Entry DOI: 10.2210/pdb6nbd/pdb
• EMDB information: 0408
• Descriptor: Hemoglobin subunit alpha, Hemoglobin subunit beta, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• Functional Keywords: heme-binding, hetero-4-mer, globin, oxygen transport
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 4
• Total formula weight: 63371.66

Authors

Herzik Jr., M.A.,Wu, M.,Lander, G.C. (deposition date: 2018-12-06, release date: 2019-02-13, Last modification date: 2024-03-20)

Primary citation

Herzik Jr., M.A.,Wu, M.,Lander, G.C.
High-resolution structure determination of sub-100 kDa complexes using conventional cryo-EM.
Nat Commun, 10:1032-1032, 2019

PubMed Abstract: Determining high-resolution structures of biological macromolecules amassing less than 100 kilodaltons (kDa) has been a longstanding goal of the cryo-electron microscopy (cryo-EM) community. While the Volta phase plate has enabled visualization of specimens in this size range, this instrumentation is not yet fully automated and can present technical challenges. Here, we show that conventional defocus-based cryo-EM methodologies can be used to determine high-resolution structures of specimens amassing less than 100 kDa using a transmission electron microscope operating at 200 keV coupled with a direct electron detector. Our ~2.7 Å structure of alcohol dehydrogenase (82 kDa) proves that bound ligands can be resolved with high fidelity to enable investigation of drug-target interactions. Our ~2.8 Å and ~3.2 Å structures of methemoglobin demonstrate that distinct conformational states can be identified within a dataset for proteins as small as 64 kDa. Furthermore, we provide the sub-nanometer cryo-EM structure of a sub-50 kDa protein.

PubMed: 30833564
DOI: 10.1038/s41467-019-08991-8

Experimental method

ELECTRON MICROSCOPY (3.2 Å)