Exploiting the anisotropy of anomalous scattering boosts the phasing power of SAD and MAD experiments.

ABSTRACT: The X-ray polarization anisotropy of anomalous scattering in crystals of brominated nucleic acids and selenated proteins is shown to have significant effects on the diffraction data collected at an absorption edge. For conventionally collected single- or multi-wavelength anomalous diffraction data, the main manifestation of the anisotropy of anomalous scattering is the breakage of the equivalence between symmetry-related reflections, inducing intensity differences between them that can be exploited to yield extra phase information in the structure-solution process. A new formalism for describing the anisotropy of anomalous scattering which allows these effects to be incorporated into the general scheme of experimental phasing methods using an extended Harker construction is introduced. Thi

SUBMITTER: Schiltz M 

PROVIDER: S-EPMC2467528 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature