AUTHOR=Takaba Kiyofumi , Maki-Yonekura Saori , Inoue Satoru , Hasegawa Tatsuo , Yonekura Koji TITLE=Protein and Organic-Molecular Crystallography With 300kV Electrons on a Direct Electron Detector JOURNAL=Frontiers in Molecular Biosciences VOLUME=7 YEAR=2021 URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2020.612226 DOI=10.3389/fmolb.2020.612226 ISSN=2296-889X ABSTRACT=

Electron 3D crystallography can reveal the atomic structure from undersized crystals of various samples owing to the strong scattering power of electrons. Here, a direct electron detector DE64 was tested for small and thin crystals of protein and an organic molecule using a JEOL CRYO ARM 300 electron microscope. The microscope is equipped with a cold-field emission gun operated at an accelerating voltage of 300 kV, quad condenser lenses for parallel illumination, an in-column energy filter, and a stable rotational goniometer stage. Rotational diffraction data were collected in an unsupervised manner from crystals of a heme-binding enzyme catalase and a representative organic semiconductor material Ph-BTBT-C10. The structures were determined by molecular replacement for catalase and by the direct method for Ph-BTBT-C10. The analyses demonstrate that the system works well for electron 3D crystallography of these molecules with less damaging, a smaller point spread, and less noise than using the conventional scintillator-coupled camera.