title: Direct-method SAD phasing of proteins enhanced by the use of intrinsic bimodal phase distributions in the subsequent phase-improvement process.
abstract: A modified SAD (single-wavelength anomalous diffraction) phasing algorithm has been introduced in the latest version of the program OASIS. In addition to direct-method phases and figures of merit, Hendrickson-Lattman coefficients that correspond to the original unresolved bimodal phase distributions are also output and used in subsequent phase-improvement procedures in combination with the improved phases. This provides the possibility of rebreaking the SAD phase ambiguity using the ever-improving phases resulting from the phase-improvement process. Tests using experimental SAD data from six known proteins showed that in all cases the new treatment produced significant improved results.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Li-Jie
authors.initials: LJ
authors.lastname: Wu
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Yuan-Xin
authors.initials: YX
authors.lastname: Gu
authors.forename: Chao-De
authors.initials: CD
authors.lastname: Zheng
authors.forename: Hai-Fu
authors.initials: HF
authors.lastname: Fan
mesh_terms: D011506:Proteins / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D011506:Proteins