title: Direct-method-aided phasing of MAD data.
abstract: The direct methods of breaking the phase ambiguity intrinsic in one-wavelength anomalous scattering (OAS) data and MAD phasing are powerful methods in their own rights. In a different context, in addition to their success in phasing OAS data, direct methods can also be useful in the treatment of MAD data. The idea has been tested with the MAD data at 2.5 A resolution from the protein human adenosine kinase [Mathews et al. (1998), Biochemistry, 37, 15607--15620]. The results showed that the incorporation of direct methods in MAD phasing led to a significant improvement of phases over those obtained from the conventional MAD phasing method alone, as indicated by improved map correlation coefficients (with the existing model), reduced phase errors by 4.5 degrees and improved map connectivity.
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
authors.forename: Y X
authors.initials: YX
authors.lastname: Gu
authors.forename: Y D
authors.initials: YD
authors.lastname: Liu
authors.forename: Q
authors.initials: Q
authors.lastname: Hao
authors.forename: S E
authors.initials: SE
authors.lastname: Ealick
authors.forename: H F
authors.initials: HF
authors.lastname: Fan
mesh_terms: D000248:Adenosine Kinase / Q000737:chemistry*; D018360:Crystallography, X-Ray / Q000379:methods*; D003627:Data Interpretation, Statistical; D006801:Humans; D008958:Models, Molecular; D011487:Protein Conformation; D012542:Scattering, Radiation
chemical_list: D000248:Adenosine Kinase