Enhancing MAD F(A) data for substructure determination.
Enhancing MAD F(A) data for substructure determination.
复制标题
增强用于子结构确定的 MAD F(A) 数据。
DOI：
10.1107/s0907444910025783
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Xu,Hongliang
中科院分区：
文献类型：
--
作者：
Xu,Hongliang
重原子亚结构的确定是确定未知大分子结构的关键步骤。双空间（shake - bake）循环是利用多波长异常衍射估计的FA数据定位子结构（重）原子的一种非常有效的方法。然而，估计的FA容易受到几个波长的单个强度测量误差的累积以及对异常原子散射校正f '和f "的不准确估计的影响。本文采用了一种新的统计计算方法，将多个FA估计合并为一个平均数据集，进一步提高了异常幅度估计的质量。18个硒原子子结构的测定结果为使用这种方法定位异常散射体提供了令人信服的证据。
Heavy-atom substructure determination is a critical step in phasing an unknown macromolecular structure. Dual-space (Shake-and-Bake) recycling is a very effective procedure for locating the substructure (heavy) atoms using FA data estimated from multiple-wavelength anomalous diffraction. However, the estimated FA are susceptible to the accumulation of errors in the individual intensity measurements at several wavelengths and from inaccurate estimation of the anomalous atomic scattering corrections f′ and f′′. In this paper, a new statistical and computational procedure which merges multiple FA estimates into an averaged data set is used to further improve the quality of the estimated anomalous amplitudes. The results of 18 Se-atom substructure determinations provide convincing evidence in favor of using such a procedure to locate anomalous scatterers.