Correction of X-ray intensities from single crystals containing lattice-translocation defects
Correction of X-ray intensities from single crystals containing lattice-translocation defects
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DOI：
10.1107/s0907444904026721
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发表时间：
2005-01-01
期刊：
影响因子：
--
通讯作者：
Steitz, TA
中科院分区：
文献类型：
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作者：
Wang, JM;Kamtekar, S;Steitz, TA
1954年，豪威尔斯和同事描述了一种由晶格移位缺陷引起的咪唑高铁血红蛋白晶体的不寻常衍射图案。在这些晶体中，两个相同的晶格共存为一个单一的连贯马赛克块，但由一个固定的向量相对于彼此平移。观察到的结构是两个相同但平移的结构的加权和，每个结构来自每个晶格;观察到的结构因子是两个结构因子的加权矢量和，具有相同的单位振幅但相移。本文介绍了一种通过X射线强度校正从重排列的单点阵中获得观测结构因子的单位振幅的一般方法。应用该方法，采用多同晶置换和多波长反常色散方法，以2.2埃的分辨率测定了phi 29 DNA聚合酶的晶体结构。
In 1954, Howells and colleagues described an unusual diffraction pattern from imidazole methemoglobin crystals caused by lattice-translocation defects. In these crystals, two identical lattices coexist as a single coherent mosaic block, but are translated by a fixed vector with respect to each other. The observed structure is a weighted sum of the two identical but translated structures, one from each lattice; the observed structure factors are a weighted vector sum of the two structure factors with identical unit amplitudes but shifted phases. A general procedure is described to obtain the unit amplitudes of observed structure factors from a realigned single lattice through an X-ray intensity correction. An application of this procedure is made to determine the crystal structure of phi29 DNA polymerase at 2.2 Angstrom resolution using multiple isomorphous replacement and multiwavelength anomalous dispersion methods.