Purification, crystallization and preliminary crystallographic analysis of the 16S rRNA methyltransferase RsmI from Escherichia coli.
Purification, crystallization and preliminary crystallographic analysis of the 16S rRNA methyltransferase RsmI from Escherichia coli.
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DOI：
10.1107/s2053230x14016999
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发表时间：
2014-09
期刊：
影响因子：
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通讯作者：
Mohan Zhao;Li Wang;Heng Zhang;Yuhui Dong;Y. Gong;Linbo Zhang;Jian Wang
中科院分区：
文献类型：
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作者：
Mohan Zhao;Li Wang;Heng Zhang;Yuhui Dong;Y. Gong;Linbo Zhang;Jian Wang
RsmI和RsmH是adomet依赖的甲基转移酶，分别负责大肠杆菌16S rRNA C1402的2'- o -甲基化和N(4)-甲基化。该位点的修改被发现在微调p位点的形状和功能以提高解码保真度方面发挥作用。研究C1402同时被RsmI和RsmH甲基化的机制是非常有趣的。最近已经确定了RsmH与AdoMet和胞苷配合物的晶体结构，并为该位点的N(4)-甲基化提供了一些启示。本文报道了RsmI的纯化、结晶及其初步的晶体学分析。采用坐滴气相扩散法对RsmI与AdoMet进行共结晶，并在BSRF光束线1W2B上采集分辨率为2.60 Å的x射线衍射数据。该晶体每个不对称单元包含3个分子，属于空间群C2，单位胞参数a = 121.9, b = 152.5, c = 54.2 Å， β = 93.4°。
RsmI and RsmH are AdoMet-dependent methyltransferases that are responsible for the 2'-O-methylation and N(4)-methylation of C1402 of Escherichia coli 16S rRNA, respectively. Modification of this site has been found to play a role in fine-tuning the shape and function of the P-site to increase the decoding fidelity. It is interesting to study the mechanism by which C1402 can be methylated by both RsmI and RsmH. The crystal structure of RsmH in complex with AdoMet and cytidine has recently been determined and provided some implications for N(4)-methylation of this site. Here, the purification and crystallization of RsmI as well as its preliminary crystallographic analysis are reported. Co-crystallization of RsmI with AdoMet was carried out by the sitting-drop vapour-diffusion method and X-ray diffraction data were collected to 2.60 Å resolution on beamline 1W2B at BSRF. The crystal contained three molecules per asymmetric unit and belonged to space group C2, with unit-cell parameters a = 121.9, b = 152.5, c = 54.2 Å, β = 93.4°.