title: Multi-crystal native SAD analysis at 6 keV.
abstract: Anomalous diffraction signals from typical native macromolecules are very weak, frustrating their use in de novo structure determination. Here, native SAD procedures are described to enhance signal to noise in anomalous diffraction by using multiple crystals in combination with synchrotron X-rays at 6 keV. Increased anomalous signals were obtained at 6 keV compared with 7 keV X-ray energy, which was used for previous native SAD analyses. A feasibility test of multi-crystal-based native SAD phasing was performed at 3.2 Å resolution for a known tyrosine protein kinase domain, and real-life applications were made to two novel membrane proteins at about 3.0 Å resolution. The three applications collectively serve to validate the robust feasibility of native SAD phasing at lower energy.
authors.affiliation: NYCOMPS, New York Structural Biology Center, New York, NY 10032, USA.
authors.forename: Qun
authors.initials: Q
authors.lastname: Liu
authors.affiliation: NYCOMPS, New York Structural Biology Center, New York, NY 10032, USA.
authors.forename: Youzhong
authors.initials: Y
authors.lastname: Guo
authors.affiliation: NYCOMPS, New York Structural Biology Center, New York, NY 10032, USA.
authors.forename: Yanqi
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Cai
authors.affiliation: Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Assur
authors.affiliation: Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA.
authors.forename: Filippo
authors.initials: F
authors.lastname: Mancia
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Mark I
authors.initials: MI
authors.lastname: Greene
authors.affiliation: NYCOMPS, New York Structural Biology Center, New York, NY 10032, USA.
authors.forename: Wayne A
authors.initials: WA
authors.lastname: Hendrickson
mesh_terms: D001412:Bacillus subtilis / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray / Q000379:methods*; D066246:ErbB Receptors / Q000737:chemistry*; D006801:Humans; D008089:Listeria monocytogenes / Q000737:chemistry; D026901:Membrane Transport Proteins / Q000737:chemistry; D008958:Models, Molecular; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D015203:Reproducibility of Results; D017356:Synchrotrons
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D066246:ErbB Receptors
keywords: anomalous diffraction; light-atom-only native SAD; phase determination; protein structure