Severe diffraction anisotropy, rotational pseudosymmetry and twinning complicate the refinement of a pentameric coiled-coil structure of NSP4 of rotavirus

Abstract

The crystal structure of the region spanning residues 95–146 of the rotavirus nonstructural protein NSP4 from the asymptomatic human strain ST3 was determined at a resolution of 2.5 Å. Severe diffraction anisotropy, rotational pseudosymmetry and twinning complicated the refinement of this structure. A systematic explanation confirming the crystal pathologies and describing how the structure was successfully refined is given in this report.