Molecular Replacement Method at Low Resolution: Optimum Strategy and Intrinsic Limitations as Determined by Calculations on Icosahedral Virus Models
Molecular Replacement Method at Low Resolution: Optimum Strategy and Intrinsic Limitations as Determined by Calculations on Icosahedral Virus Models
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低分辨率分子替换方法：二十面体病毒模型计算确定的最佳策略和内在限制
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发表时间：
1983
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影响因子：
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通讯作者：
I. Rayment
中科院分区：
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作者：
I. Rayment
一个广泛的一系列的相位模型结构因素的改进已经进行了确定的范围和限制，在低分辨率的实空间对称平均。这些计算用于推导和证明用于以22.5 μ k分辨率解析多瘤病毒衣壳结构的策略[Rayment，Baker，Caspar & Murakami（1982）. Nature（伦敦），295，110-115].计算表明：（1）可以成功地细化各种模型的相位;（2）约束振幅和观测振幅之间的低R因子（，-，10%）对应于计算相位和真实相位之间的小误差;（3）在收敛到低R因子时，初始定相模型引入的最终相位中没有残留偏差。模型计算也被用来确定所施加的系列终止，未测量的数据，随机误差的数据和分子包络的作用相细化的限制。
An extensive series of phase refinements on model structure factors has been carried out to determine the scope and limitations of real-space symmetry averaging at low resolution. These calculations were used to derive and justify the strategy used to solve the structure of polyoma virus capsids at 22.5 ,/k resolution [Rayment, Baker, Caspar & Murakami (1982). Nature (London), 295, 110-115]. The calculations showed (1) that phases from a wide variety of models can be successfully refined; (2) a low R factor (,-,10%) between the constrained and observed amplitudes corresponds to a small error between the calculated and true phases; (3) on convergence to a low R factor there is no residual bias in the final phases introduced by the initial phasing model. The model calculations were also used to determine the limitations imposed by series termination, unmeasured data, random errors in the data and the role of the molecular envelope on the phase refinement.