Single-particle imaging without symmetry constraints at an X-ray free-electron laser

• Main Authors: Max Rose, Sergey Bobkov, Kartik Ayyer, Ruslan P. Kurta, Dmitry Dzhigaev, Young Yong Kim, Andrew J. Morgan, Chun Hong Yoon, Daniel Westphal, Johan Bielecki, Jonas A. Sellberg, Garth Williams, Filipe R.N.C. Maia, Olexander M. Yefanov, Vyacheslav Ilyin, Adrian P. Mancuso, Henry N. Chapman, Brenda G. Hogue, Andrew Aquila, Anton Barty, Ivan A. Vartanyants
• Format: Article
• Language: English
• Published: International Union of Crystallography 2018-11-01
• Series: IUCrJ
• Subjects: single-particle imaging; three-dimensional virus reconstructions; XFELs
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S205225251801120X

The analysis of a single-particle imaging (SPI) experiment performed at the AMO beamline at LCLS as part of the SPI initiative is presented here. A workflow for the three-dimensional virus reconstruction of the PR772 bacteriophage from measured single-particle data is developed. It consists of several well defined steps including single-hit diffraction data classification, refined filtering of the classified data, reconstruction of three-dimensional scattered intensity from the experimental diffraction patterns by orientation determination and a final three-dimensional reconstruction of the virus electron density without symmetry constraints. The analysis developed here revealed and quantified nanoscale features of the PR772 virus measured in this experiment, with the obtained resolution better than 10 nm, with a clear indication that the structure was compressed in one direction and, as such, deviates from ideal icosahedral symmetry.