%0 Journal Article
%T Integrative structural modeling with small angle X-ray scattering profiles
%A Dina Schneidman-Duhovny
%A Seung Kim
%A Andrej Sali
%J BMC Structural Biology
%D 2012
%I BioMed Central
%R 10.1186/1472-6807-12-17
%X SAXS is becoming a widely used technique for low-resolution structural characterization of macromolecules in solution [1-5]. The major advantage of SAXS compared to other structural characterization techniques is that it can be performed under a wide variety of solution conditions, including near physiological conditions, and for a wide range of molecular sizes. The experiment is typically performed with ~0.5¨C10.0£¿mg/mL of a macromolecular sample in a ~15¨C30 ¦ÌL volume, and usually takes less than a few minutes on a well-equipped synchrotron beam line. In addition, recent technological advances allow in-house laboratory data collection without a beam line X-ray source.The SAXS experiment results in a small-angle X-ray scattering intensity of a sample (a macromolecule in a buffer) as a function of spatial frequency [6-8]. The SAXS profile of the macromolecule is then produced by subtracting the SAXS profile of the buffer from the SAXS profile of the sample. Because of rotational averaging, the information content of a SAXS profile is significantly lower compared to that of a diffraction pattern in X-ray crystallography or even a density map from electron microscopy (EM). Nevertheless, SAXS can provide shape information about proteins and macromolecular assemblies that are not amenable to X-ray crystallography, NMR spectroscopy, or EM. Information about the radius of gyration, volume, and mass can be easily extracted from the profile [8,9]. The profile can be converted into an approximate distribution of pairwise electron distances in the macromolecule (i.e. the pair-distribution function) via a Fourier transform [7,8,10]. Moreover, SAXS can be used to study the dynamics of the system [11,12], not only a static structure.SAXS profiles can be used for computation of so called ab initio 3D shapes that are consistent with the measured pair-distribution function [13-15]. SAXS profiles can also be used for atomic resolution modeling in multiple modeling applications, includ
%K Small Angle X-ray Scattering (SAXS)
%K Protein structure prediction
%K Macromolecular assembly
%K Integrative modeling
%U http://www.biomedcentral.com/1472-6807/12/17