Luo M, Vriend G, Kamer G, Rossmann M G
Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907.
Acta Crystallogr B. 1989 Feb 1;45 ( Pt 1):85-92. doi: 10.1107/s0108768188010894.
The structure of Mengo virus was determined to 3.0 A resolution using human rhinovirus 14 as an initial phasing model at 8.0 A resolution. Oscillation diffraction photographs were collected at the Cornell High Energy Synchrotron Source using orthorhombic Mengo virus crystals. The crystal space group was P2(1)2(1)2(1), a = 441.4, b = 427.3 and c = 421.9 A, with one icosahedral particle per asymmetric unit, giving 60-fold noncrystallographic redundancy. The orientations of the four viral particles in the unit cell were determined with a rotation function. Their positions relative to the crystallographic symmetry axes were found by a combination of Patterson-function analysis and a subsequent R-factor search using human rhinovirus 14 atomic coordinates as a model. The initial phases to 8.0 A resolution were then computed by placing human rhinovirus 14 particles in the orientations and positions of Mengo virus particles. These phases were improved by ten cycles of real-space molecular replacement averaging. Phases between 8.0 and 3.0 A resolution were obtained by molecular replacement phase extension. One or two reciprocal-space lattice points were used for each extension followed by two cycles of averaging.
以分辨率为8.0 Å的人鼻病毒14作为初始相位模型，将门戈病毒的结构解析到了3.0 Å的分辨率。使用正交晶系的门戈病毒晶体，在康奈尔高能同步加速器源收集了振荡衍射照片。晶体空间群为P2(1)2(1)2(1)，a = 441.4，b = 427.3，c = 421.9 Å，每个不对称单元中有一个二十面体颗粒，具有60倍的非晶体学冗余度。通过旋转函数确定了晶胞中四个病毒颗粒的取向。通过帕特森函数分析以及随后使用人鼻病毒14原子坐标作为模型的R因子搜索，找到了它们相对于晶体学对称轴的位置。然后，通过将人鼻病毒14颗粒放置在门戈病毒颗粒的取向和位置上，计算出了分辨率为8.0 Å的初始相位。通过十个周期的实空间分子置换平均，对这些相位进行了改进。通过分子置换相位扩展获得了8.0至3.0 Å分辨率之间的相位。每次扩展使用一两个倒易空间晶格点，然后进行两个周期的平均。
