Neutron and X-ray solution scattering provide insights into biomolecular structure and function.

Neutron and X-ray small-angle scattering techniques have made significant advances in their applications in structural molecular biology. They have become important tools for studying the structural basis for biomolecular function, revealing details of protein and DNA structure, as well as functionally important conformational flexibility and interactions. More powerful neutron and X-ray sources are now available which enable faster data acquisition on lower concentration samples, as well as time-resolved studies in the case of synchrotron sources. This source development has been accompanied by instrument development and advances in scattering techniques. At the same time, advances in molecular biology that facilitate preparation of samples have made available more biological molecules suitable for study by scattering techniques. In this review we briefly describe the basic theory and practice of small-angle scattering and follow with examples of its application to studying the conformations of biomolecules in solution, as well as within functional complexes.