Crystal structures of the Bacillus subtilis prophage lytic cassette proteins XepA and YomS

Freitag-Pohl, Stefanie; Jasilionis, Andrius; Håkansson, Maria; Svensson, L. Anders; Kovačič, Rebeka; Welin, Martin; Watzlawick, Hildegard; Wang, Lei; Altenbuchner, Josef; Płotka, Magdalena; Kaczorowska, Anna Karina; Kaczorowski, Tadeusz; Nordberg Karlsson, Eva; Al-Karadaghi, Salam; Walse, Björn; Aevarsson, Arnthór; Pohl, Ehmke

Abstract

For the extraction of the best possible X-ray diffraction data from macromolecular crystals, accurate positioning of the crystals with respect to the X-ray beam is crucial. In addition, information about the shape and internal defects of crystals allows the optimization of data-collection strategies. Here, it is demonstrated that the X-ray beam available on the macromolecular crystallo­graphy beamline P14 at the high-brilliance synchrotron-radiation source PETRA III at DESY, Hamburg, Germany can be used for high-energy phase-contrast microtomography of protein crystals mounted in an optically opaque lipidic cubic phase matrix. Three-dimensional tomograms have been obtained at X-ray doses that are substantially smaller and on time scales that are substantially shorter than those used for diffraction-scanning approaches that display protein crystals at micrometre resolution. Adding a compound refractive lens as an objective to the imaging setup, two-dimensional imaging at sub-micrometre resolution has been achieved. All experiments were performed on a standard macromolecular crystallography beamline and are compatible with standard diffraction data-collection workflows and apparatus. Phase-contrast X-ray imaging of macromolecular crystals could find wide application at existing and upcoming low-emittance synchrotron-radiation sources.

Citation

Freitag-Pohl, S., Jasilionis, A., Håkansson, M., Svensson, L. A., Kovačič, R., Welin, M., …Pohl, E. (2019). Crystal structures of the Bacillus subtilis prophage lytic cassette proteins XepA and YomS. Acta Crystallographica Section D: Structural Biology, 75(11), 1028-1039. https://doi.org/10.1107/s2059798319013330

• Journal Article Type: Article
• Acceptance Date: Sep 28, 2019
• Publication Date: Nov 1, 2019
• Deposit Date: Nov 11, 2019
• Publicly Available Date: Nov 13, 2019
• Journal: Acta crystallographica. Section D, Structural biology.
• Print ISSN: 2059-7983
• Publisher: International Union of Crystallography
• Peer Reviewed: Peer Reviewed
• Volume: 75
• Issue: 11
• Pages: 1028-1039
• DOI: https://doi.org/10.1107/s2059798319013330