Small angle neutron and X-ray scattering in structural biology: recent examples from the literature

Small angle scattering can provide unique structural information on the shape, domain organisation, and interactions of biomacromolecules in solution. Small angle neutron scattering (SANS) combined with deuterium labelling makes it possible to define the positions of specific components within a complex while small angle X-ray scattering (SAXS) provides more precise data on the overall shape. Here I review four recent publications, three of which were presented at the Neutrons in Biology meeting at the STFC Rutherford Appleton Laboratory in July 2007, that utilise SANS, SAXS, and complementary techniques to define the solution structure of large multidomain proteins and macromolecular complexes. These four papers emphasise the critical importance of sample quality and characterisation as well as the important role played by complementary techniques in building structural models based on small angle scattering data. They show the ability of SANS and SAXS in determining solution structures provides an important complementary structural technique for large, flexible, and glycosylated proteins where high resolution structural techniques, such as crystallography and NMR, cannot be applied.