Guo Hong Yue, Gao Zeng Qiang, Zhang Heng, Wei Yong, Xu Jian Hua, Wang Wen Ya, Yan Ai Xia, Dong Yu Hui
College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2013 Jun;69(Pt 6):640-2. doi: 10.1107/S1744309113006611. Epub 2013 May 24.
RlmM is an AdoMet-dependent methyltransferase that is responsible for 2'-O-methylation of C2498 in the peptidyl-transferase loop of bacterial 23S rRNA. This modification occurs before assembly of the 50S ribosomal subunit, and lack of C2498 methylation can cause a slight reduction in bacterial fitness. Here, the purification and crystallization of RlmM from Escherichia coli as well as its preliminary crystallographic analysis are presented. Cocrystallization of RlmM with AdoMet was carried out and X-ray diffraction data were collected to a resolution of 2.30 Å on beamline BL17U at the SSRF. However, electron density for AdoMet cannot be observed by comprehensive crystallographic analysis, indicating that it is not bound by RlmM during the cocrystallization process. The structure was solved by molecular replacement and refinement is in progress. The crystal contained one molecule in the asymmetric unit and belonged to space group P2(1), with unit-cell parameters a = 56.07, b = 59.38, c = 54.35 Å, β = 94.84°, which differs from the P3(1) or P3(1)21 space groups of previously reported RlmM structures (PDB entries 4auk, 4atn and 4b17).
RlmM是一种依赖于腺苷甲硫氨酸（AdoMet）的甲基转移酶，负责细菌23S rRNA肽基转移酶环中C2498位点的2'-O-甲基化修饰。这种修饰发生在50S核糖体亚基组装之前，缺乏C2498甲基化会导致细菌适应性略有下降。本文介绍了来自大肠杆菌的RlmM的纯化、结晶及其初步晶体学分析。进行了RlmM与AdoMet的共结晶，并在上海光源的BL17U光束线上收集了分辨率为2.30 Å的X射线衍射数据。然而，通过全面的晶体学分析未观察到AdoMet的电子密度，这表明在共结晶过程中它未与RlmM结合。该结构通过分子置换法解析，目前正在进行精修。晶体的不对称单元中包含一个分子，属于空间群P2(1)，晶胞参数为a = 56.07，b = 59.38，c = 54.35 Å，β = 94.84°，这与先前报道的RlmM结构（PDB编号4auk、4atn和4b17）的P3(1)或P3(1)21空间群不同。
