title: Serial crystallographic analysis of protein isomorphous replacement data from a mixture of native and derivative microcrystals.
abstract: A post-experimental identification/purification procedure similar to that described in Zhang et al. [(2015), IUCrJ, 2, 322-326] has been proposed for use in the treatment of multiphase protein serial crystallography (SX) diffraction snapshots. As a proof of concept, the procedure was tested using theoretical serial femtosecond crystallography (SFX) data from a mixture containing native and derivatized crystals of a protein. Two known proteins were taken as examples. Multiphase diffraction snapshots were subjected to two rounds of indexing using the program CrystFEL [White et al. (2012). J. Appl. Cryst. 45, 335-341]. In the first round, an ab initio indexing was performed to derive a set of approximate primitive unit-cell parameters, which are roughly the average of those from the native protein and the derivative. These parameters were then used in a second round of indexing as input to CrystFEL. The results were then used to separate the diffraction snapshots into two subsets corresponding to the native and the derivative. For each test sample, integration of the two subsets of snapshots separately led to two sets of three-dimensional diffraction intensities, one belonging to the native and the other to the derivative. Based on these two sets of intensities, a conventional single isomorphous replacement (SIR) procedure solved the structure easily.
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, People's Republic of China.
authors.forename: Deqiang
authors.initials: D
authors.lastname: Yao
authors.affiliation: School of Life Sciences, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Yuanxin
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Haifu
authors.initials: H
authors.lastname: Fan
mesh_terms: D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000737:chemistry*; D018797:Cell Cycle Proteins / Q000737:chemistry*; D003460:Crystallization; D016952:Legionella pneumophila / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry*; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction
chemical_list: D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; C557631:NCS2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins
keywords: isomorphous replacement; multiphase diffraction; serial crystallography