title: Cross-Validation of Data Compatibility Between Small Angle X-ray Scattering and Cryo-Electron Microscopy.
abstract: Cryo-electron microscopy (EM) and small angle X-ray scattering (SAXS) are two different data acquisition modalities often used to glean information about the structure of large biomolecular complexes in their native states. A SAXS experiment is generally considered fast and easy but unveils the structure at very low resolution, whereas a cryo-EM experiment needs more extensive preparation and postacquisition computation to yield a three-dimensional (3D) density map at higher resolution. In certain applications, we may need to verify whether the data acquired in the SAXS and cryo-EM experiments correspond to the same structure (e.g., before reconstructing the 3D density map in EM). In this article, a simple and fast method is proposed to verify the compatibility of the SAXS and EM experimental data. The method is based on averaging the two-dimensional correlation of EM images and the Abel transform of the SAXS data. Orientational preferences are known to exist in cryo-EM experiments, and we also consider these effects on our method. The results are verified on simulations of conformational states of large biomolecular complexes.
authors.affiliation: 1 Department of Mechanical Engineering, Johns Hopkins University , Baltimore, Maryland.
authors.forename: Jin Seob
authors.initials: JS
authors.lastname: Kim
authors.affiliation: 2 Center for Imaging Science, Johns Hopkins University , Baltimore, Maryland.
authors.forename: Bijan
authors.initials: B
authors.lastname: Afsari
authors.affiliation: 1 Department of Mechanical Engineering, Johns Hopkins University , Baltimore, Maryland.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Chirikjian
mesh_terms: D000465:Algorithms; D020285:Cryoelectron Microscopy / Q000592:standards*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008958:Models, Molecular; D011487:Protein Conformation; D017470:Receptors, Glutamate / Q000737:chemistry; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction / Q000592:standards*
chemical_list: D046911:Macromolecular Substances; D017470:Receptors, Glutamate
keywords: Abel transform; SAXS; compatibility; correlation function; cryo-EM; preferred orientations