XRAY CRYSTALLOGRAPHY OF CATALYTIC RNA

我们正在进行一些催化剂的结构测定 用X射线结晶学研究了RNA分子和催化RNA结构域。在……里面 在过去的几年里，我们开发了新的方法来获得 使用“RNA”的大RNA分子的衍射性晶体 结晶模块“。这些部分被设计成 靶RNA的初级序列以呈现良好分化 促进分子间接触的分子表面和晶体 成长。在两个方面都取得了进展。 在国际象棋中提供华丽的X光片。1)70-核苷酸的晶体 在六角形结构中获得了自分裂的第II族内含子的结构域 弱衍射至4A的空间群(a=94 A，c=230 A) 与实验室X射线源的分辨率。闪存的优化 国际象棋A-1束线的冷却条件和数据采集 ADSC Quantum-1区域探测器产生了一个完整的本地数据集 至3.4 A分辨率。重原子衍生物的制备 正在进行中。2)完整催化核的晶体 人肝炎病毒基因组RNA中自切割核酶的研究 在实验室中扩增到3.4A的Delta病毒(HDV)是 获得。用多波长反常方法解决了结构问题 使用来自弯曲的同步辐射的衍射(MAD) 国家同步加速器光源的磁铁(布鲁克海文国家 纽约实验室)，获得了2.7A分辨率的数据。 改进的闪光冷却和高亮度和准直性 在国际象棋F1光束线上可用的X射线使我们能够收集 卓越的本机数据集，分辨率超过2.4 A ADSC Quantum-4面阵探测器。对结构进行优化以防止 这一更高分辨率的数据集正在进行中。

We are pursuing structure determination of a number of catalytic RNA molecules and catalytic RNA domains by X-ray crystallography. In the past several years we have developed novel methods to obtain diffraction quality crystals of large RNA molecules which employ "RNA crystallization modules". These are moieties engineered into the primary sequence of the target RNAs to present well-differentiated molecular surfaces that promote inter-molecular contacs, and crystal growth. Progress has been made in two fronts employing the high brilliance X-rays available at CHESS. 1) Crystals of a 70-nucleotide domain of a self-splcing Group II intron were obtained in a hexagonal space group (a=94 A, c=230 A) which diffracted weakly to 4 A resolution with a laboratory X-ray source. Optimization of flash cooling conditions, and data collection at beam-line A-1 of CHESS with the ADSC Quantum-1 area detector produced a complete native data-set to 3.4 A resolution. Preparation of heavy atom derivatives is underway. 2) Crystals of the complete catalytic core of the self-cleaving ribozyme from the genomic RNA of the human Hepatitis Delta Virus (HDV) which diffractedto 3.4 A in the laboratory, were obtained. The structure was solved by multiwavelength anomalous diffraction (MAD) employing synchrotron radiation from a bending magnet at the National Synchrotron Light Source (Brookhaven National Laboratory, NY) where data to 2.7 A resolution were obtained. Improved flash cooling and the high brilliance and collimation of X-rays available at beam-line F1 of CHESS allowed us to collect a superior native data-set which extends to beyond 2.4 A resolution on the ADSC Quantum-4 area detector. Refinement of the structure against this higher resolution data-set is in progress.