Fukuyama K, Abdel-Meguid S S, Johnson J E, Rossmann M G
J Mol Biol. 1983 Jul 15;167(4):873-90. doi: 10.1016/s0022-2836(83)80116-8.
A T = 1 empty aggregate of alfalfa mosaic virus coat protein had been crystallized in a hexagonal unit cell and its orientation was determined with the rotation function. A single heavy-atom derivative has now been prepared and the position of the two Hg atoms per protein subunit were determined using a systematic Patterson search procedure, given the particle orientation. Phases, initially determined by single isomorphous replacement, were refined by six cycles of electron density averaging and solvent leveling to produce a 4.5 A resolution electron density map. The protein coat is confined between 95 and 58 A radius. The subunit boundary could be delineated easily. It has a central cavity reminiscent of the beta-barrel in other spherical plant viruses, but its topology could not be determined unambiguously. The spherical particle has large holes at the 5-fold axes, consistent with previous observations. The subunits have substantial interactions at the 2 and 3-fold axes. The structure of the elongated particles is discussed in relation to these results.
一个T = 1的苜蓿花叶病毒外壳蛋白空聚集体已在六方晶胞中结晶，其取向通过旋转函数确定。现在制备了一种单重原子衍生物，并利用系统帕特森搜索程序确定了每个蛋白质亚基中两个汞原子的位置，已知粒子取向。最初通过单同晶置换确定的相位，通过六个周期的电子密度平均和溶剂平整进行了精修，以生成分辨率为4.5 Å的电子密度图。蛋白质外壳限制在半径95至58 Å之间。亚基边界很容易划定。它有一个中央腔，让人联想到其他球形植物病毒中的β桶，但无法明确确定其拓扑结构。球形颗粒在五重轴处有大洞，与先前的观察结果一致。亚基在二重和三重轴处有大量相互作用。结合这些结果讨论了细长颗粒的结构。
