title: Deformable elastic network refinement for low-resolution macromolecular crystallography.
abstract: Crystals of membrane proteins and protein complexes often diffract to low resolution owing to their intrinsic molecular flexibility, heterogeneity or the mosaic spread of micro-domains. At low resolution, the building and refinement of atomic models is a more challenging task. The deformable elastic network (DEN) refinement method developed previously has been instrumental in the determinion of several structures at low resolution. Here, DEN refinement is reviewed, recommendations for its optimal usage are provided and its limitations are discussed. Representative examples of the application of DEN refinement to challenging cases of refinement at low resolution are presented. These cases include soluble as well as membrane proteins determined at limiting resolutions ranging from 3 to 7 Å. Potential extensions of the DEN refinement technique and future perspectives for the interpretation of low-resolution crystal structures are also discussed.
authors.affiliation: Institute of Complex Systems (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: Gunnar F
authors.initials: GF
authors.lastname: Schröder
authors.affiliation: Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Levitt
authors.affiliation: Howard Hughes Medical Institute and Departments of Molecular and Cellular Physiology, Neurology and Neurological Sciences, Structural Biology, and Photon Science, Stanford University School of Medicine, J. H. Clark Center, 318 Campus Drive, Stanford, CA 94305, USA.
authors.forename: Axel T
authors.initials: AT
authors.lastname: Brunger
mesh_terms: D003461:Crystallography / Q000379:methods*; D004548:Elasticity; D008565:Membrane Proteins / Q000737:chemistry; D011487:Protein Conformation
chemical_list: D008565:Membrane Proteins
keywords: deformable elastic network refinement; low resolution