Institut de Biologie StructuraleGrenoble / France

Contact person(s) related to this article / GABEL Frank

Small-Angle Scattering for Structural Biology of Large Molecular Assemblies

Biological small-angle scattering

Biological small-angle scattering provides low-resolution structural information on bio-macromolecules in solution on a nanometer length-scale. The general dimensions of the molecules (radii of gyration, oligomeric state, molecular weight and interaction of different partners) can be obtained as basic information. More sophisticated approaches include ab initio shape analysis or rigid-body modeling of complexes composed of subunits with known high-resolution structure.

Modeling techniques and software have witnessed a tremendous progress over the last decade. The most recent generation combines small-angle X-ray (SAXS) and/or small-angle neutron (SANS) scattering with structural restraints from complementary techniques such as crystallography, electron microscopy and NMR.

While the majority of experiments are carried out by SAXS, SANS in combination with contrast variation (H2O/D2O ratio in the solvent) and labeling schemes (deuteration of subunits) allows focusing specifically on subunits within a complex in situ by masking the contribution of the others.

Research projects

  • Low-resolution structural study of the large aminopeptidase TET and the unfoldase PAN by SAXS/SANS (ELMA Group, IBS)
  • Methodological development of SAXS/SANS approaches in combination with NMR for the study of protein-protein and protein-RNA complexes. Collaborations with the NMR group at the Chemistry Department, TUM Munich, Germany and the NMR group at Leibniz University Hanover, Germany.
  • Characterization of intrinsically disordered proteins by SAXS/SANS (collaboration with FDP group, IBS)

Selected publications

Ibrahim, Z., Martel, A., Moulin, M., Kim, H.S., Härtlein, M., Franzetti, B. and Gabel, F. (2017) Time-resolved neutron scattering provides new insight into protein substrate processing by a AAA+ unfoldase. Sci. Rep. 7, 40948.

Hennig, J., Militti, C., Popowicz, G.M., Wang, I., Sonntag, M., Geerlof, A., Gabel, F., Gebauer, F. and Sattler, M. (2014) Structural basis for the assembly of the Sxl-Unr translation regulatory complex. Nature 515(7526), 287-290.

Appolaire A, Girard E, Colombo M, Durá MA, Moulin M, Härtlein M, Franzetti B, Gabel F. (2014) Small-angle neutron scattering reveals the assembly mode and oligomeric architecture of TET, a large, dodecameric aminopeptidase. Acta Crystallogr. D70(Pt 11), 2983-2993.

Lapinaite, A., Simon, B., Skjaerven, L., Rakwalska-Bange, M., Gabel, F. and Carlomagno, T. (2013) The structure of the box C/D enzyme reveals regulation of RNA methylation. Nature 502(7472), 519-523.

Gabel, F., Simon, B., Nilges, M., Petoukhov, M., Svergun, D. and Sattler, M. (2008) A structure refinement protocol combining NMR residual dipolar couplings and small angle scattering restraints. J. Biomol. NMR 41(4), 199-208.

A complete list of publications can be found here.