Dock A C, Lorber B, Moras D, Pixa G, Thierry J C, Giégé R
Biochimie. 1984 Mar;66(3):179-201. doi: 10.1016/0300-9084(84)90063-4.
A compilation of crystallization experiments of tRNAs published in literature as well as original results are given and discussed in this paper. Up to now 17 different tRNA species originating from Escherichia coli and from the yeast Saccharomyces cerevisiae have been crystallized. All structural tRNA families are represented, namely the tRNAs with large or small extra-loops and among them the initiator tRNAs. The tRNAs with small variable loops (4 to 5 nucleotides), e.g. tRNAAsp and tRNAPhe, yield the best diffracting crystals. Crystalline polymorphism is a common feature; about 100 different crystal forms have been observed, but only 6 among them enabled structure determination studies by X-ray diffraction. Crystallization strongly depends upon experimental parameters such as the presence of polyamines and magnesium as well as upon the purity and the molecular integrity of the tRNAs. Crystals are usually obtained by vapour diffusion methods using salts (e.g. ammonium sulfate), organic solvents (e.g. isopropanol, dioxane or 2-methyl-2,4-pentane diol) or polyethylene glycol as precipitants. A methodological strategy for crystallyzing new tRNA species is described.
本文给出并讨论了文献中发表的tRNA结晶实验汇编以及原始结果。到目前为止，已经结晶出了17种源自大肠杆菌和酿酒酵母的不同tRNA种类。所有结构tRNA家族都有代表，即具有大或小额外环的tRNA，其中包括起始tRNA。具有小可变环（4至5个核苷酸）的tRNA，如tRNAAsp和tRNAPhe，能产生衍射效果最佳的晶体。晶体多态性是一个常见特征；已经观察到约100种不同的晶体形式，但其中只有6种能够通过X射线衍射进行结构测定研究。结晶强烈依赖于实验参数，如多胺和镁的存在，以及tRNA的纯度和分子完整性。晶体通常通过气相扩散法获得，使用盐（如硫酸铵）、有机溶剂（如异丙醇、二氧六环或2-甲基-2,4-戊二醇）或聚乙二醇作为沉淀剂。本文描述了一种结晶新tRNA种类的方法策略。
