ジャーナル: Acta Crystallogr D Struct Biol / 年: 2018 タイトル: Real-space refinement in PHENIX for cryo-EM and crystallography. 著者: Pavel V Afonine / Billy K Poon / Randy J Read / Oleg V Sobolev / Thomas C Terwilliger / Alexandre Urzhumtsev / Paul D Adams / 要旨: This article describes the implementation of real-space refinement in the phenix.real_space_refine program from the PHENIX suite. The use of a simplified refinement target function enables very fast ...This article describes the implementation of real-space refinement in the phenix.real_space_refine program from the PHENIX suite. The use of a simplified refinement target function enables very fast calculation, which in turn makes it possible to identify optimal data-restraint weights as part of routine refinements with little runtime cost. Refinement of atomic models against low-resolution data benefits from the inclusion of as much additional information as is available. In addition to standard restraints on covalent geometry, phenix.real_space_refine makes use of extra information such as secondary-structure and rotamer-specific restraints, as well as restraints or constraints on internal molecular symmetry. The re-refinement of 385 cryo-EM-derived models available in the Protein Data Bank at resolutions of 6 Å or better shows significant improvement of the models and of the fit of these models to the target maps.