Evidence for a polynuclear metal ion binding site in the catalytic domain of ribonuclease P RNA
Evidence for a polynuclear metal ion binding site in the catalytic domain of ribonuclease P RNA
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DOI：
10.1093/emboj/21.9.2253
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发表时间：
2002-05-01
期刊：
影响因子：
11.4
通讯作者：
Harris, ME
中科院分区：
文献类型：
--
作者：
Christian, EL;Kaye, NM;Harris, ME
与二价金属离子的相互作用对于tRNA加工酶核糖核酸酶P（RNase P RNA）的催化RNA组分的折叠和功能是必不可少的。然而，在这个大的，高度结构化的RNA中特定金属离子相互作用的数量和位置知之甚少。使用原子诱变和定量分析的亲硫金属离子救援，我们提供的证据，金属离子相互作用的pro-R-P和pro-S-P非桥接磷酸氧在核苷酸A67在普遍保守的螺旋P4。此外，螺旋P4和相邻的单链区域（J3/4）内的第二位点修饰提供了第一个证据，金属离子与核糖核酸酶P RNA中的核苷酸碱基官能团相互作用，并揭示了催化功能重要的额外金属离子的存在。总之，这些数据与P1-P4多螺旋连接中的金属离子相互作用簇一致，该连接定义了RNase P核酶的催化核心。
Interactions with divalent metal ions are essential for the folding and function of the catalytic RNA component of the tRNA processing enzyme ribonuclease P (RNase P RNA). However, the number and location of specific metal ion interactions in this large, highly structured RNA are poorly understood. Using atomic mutagenesis and quantitative analysis of thiophilic metal ion rescue we provide evidence for metal ion interactions at the pro-R-P and pro-S-P non-bridging phosphate oxygens at nucleotide A67 in the universally conserved helix P4. Moreover, second-site modifications within helix P4 and the adjacent single stranded region (J3/4) provide the first evidence for metal ion interactions with nucleotide base functional groups in RNase P RNA and reveal the presence of an additional metal ion important for catalytic function. Together, these data are consistent with a cluster of metal ion interactions in the P1-P4 multi-helix junction that defines the catalytic core of the RNase P ribozyme.