FoXS: a web server for rapid computation and fitting of SAXS profiles

TLDR

Small angle X‑ray scattering (SAXS) is a widely used low‑resolution technique that measures a molecule’s scattering intensity as a function of spatial frequency, enabling comparisons with crystal structures, modeling of flexible proteins, and assembly of macromolecular complexes, all of which require rapid computation of SAXS profiles. The authors introduce the FoXS web server, detailing its interface and capabilities for rapid SAXS profile computation and fitting. FoXS (Fast X‑Ray Scattering) rapidly generates SAXS profiles from a given structure and aligns them with experimental data through a web‑based interface.

Abstract

Small angle X-ray scattering (SAXS) is an increasingly common technique for low-resolution structural characterization of molecules in solution. SAXS experiment determines the scattering intensity of a molecule as a function of spatial frequency, termed SAXS profile. SAXS profiles can contribute to many applications, such as comparing a conformation in solution with the corresponding X-ray structure, modeling a flexible or multi-modular protein, and assembling a macromolecular complex from its subunits. These applications require rapid computation of a SAXS profile from a molecular structure. FoXS (Fast X-Ray Scattering) is a rapid method for computing a SAXS profile of a given structure and for matching of the computed and experimental profiles. Here, we describe the interface and capabilities of the FoXS web server (http://salilab.org/foxs).