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bioRxiv · 10.1101/2021.12.21.473430

Hydrogen properties and charges in a sub-1.2 A resolution cryo-EM structure revealed by a cold field emission beam

Maki-Yonekura, S.·Kawakami, K.·Hamaguchi, T.·Takaba, K.·Yonekura, K.
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Abstract

The cold field emission (CFE) beam produces the less-attenuated contrast transfer function of electron microscopy, thereby enhancing high-resolution signals and this particularly benefits higher-resolution single particle cryogenic electron microscopy. Here, we present a sub-1.2 [A] resolution structure of a standard protein sample, apoferritin. Image data were collected with the CFE beam in a high-throughput scheme while minimizing beam tilt deviations from the coma-free axis. A difference map reveals positive densities for most hydrogen atoms in the core region of the protein complex including those in water molecules, while negative densities around acidic amino-acid side chains likely represent negative charges. The position of the hydrogen densities depends on parent bonded-atom type, which is validated by an estimated level of coordinate errors.

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Maki-Yonekura, S., Kawakami, K., Hamaguchi, T., Takaba, K., Yonekura, K.. 2021-12-22. Hydrogen properties and charges in a sub-1.2 A resolution cryo-EM structure revealed by a cold field emission beam. https://doi.org/10.1101/2021.12.21.473430

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