Cooperative RNP assembly: complementary rescue of structural defects by protein and RNA subunits of archaeal RNase P.
Cooperative RNP assembly: complementary rescue of structural defects by protein and RNA subunits of archaeal RNase P.
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DOI：
10.1016/j.jmb.2011.05.012
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发表时间：
2011-08-12
影响因子：
5.6
通讯作者：
Gopalan V
中科院分区：
文献类型：
--
作者：
Chen WY;Xu Y;Cho IM;Oruganti SV;Foster MP;Gopalan V
RNase P是一种核糖核蛋白（RNP）复合物，它利用Mg 2+依赖的RNA催化剂切割前体tRNA（pre-tRNA）的5 ′-前导序列并产生成熟的tRNA。细菌RNase P蛋白（RPP）通过促进底物结合、Mg 2+配位和产物释放来辅助RNase P RNA（RPR）催化。酵母RNA酶P由一个RPR和至少四个RPP组成，RPP具有真核同源物并作为两个二元复合物（POP5·RPP 30和RPP 21·RPP 29）起作用。在这项研究中，我们采用了先前表征的底物-酶缀合物[前-tRNATyr-詹氏甲烷醛球菌（Mja）RPR]来研究古细菌RPR中膨胀螺旋结构中普遍保守的尿苷的功能作用。与野生型相比，缺失这种凸起的尿苷导致pre-tRNATyr-Mja Δ U RPR的自切割率降低80倍，并且这种缺陷在添加任一RPP对后部分改善。古细菌突变RPR中的催化缺陷反映了细菌RPR中的报道，并突出了它们活性位点的平行性。此外，通过等温滴定量热法和NMR光谱法评估，在与其二元伴侣RPP 21组装中有缺陷的激烈火球菌（Pfu）RPP 29的N-末端缺失突变体在与同源Pfu RPR重构时是功能性的。总的来说，这些结果表明，古细菌RPPs能够弥补其同源RPR的结构缺陷，反之亦然，并提供了引人注目的例子，合作的亚基相互作用的驱动古细菌RNase P向其功能构象的关键。(236字）
RNase P is a ribonucleoprotein (RNP) complex that utilizes a Mg2+-dependent RNA catalyst to cleave the 5′-leader of precursor tRNAs (pre-tRNAs) and generate mature tRNAs. The bacterial RNase P protein (RPP) aids RNase P RNA (RPR) catalysis by promoting substrate binding, Mg2+ coordination, and product release. Archaeal RNase P comprises an RPR and at least four RPPs, which have eukaryal homologs and function as two binary complexes (POP5•RPP30 and RPP21•RPP29). In this study, we employed a previously characterized substrate-enzyme conjugate [pre-tRNATyr-Methanocaldococcus jannaschii (Mja) RPR] to investigate the functional role of a universally conserved uridine in a bulge-helix structure in archaeal RPRs. Deletion of this bulged uridine resulted in an 80-fold decrease in the self-cleavage rate of pre-tRNATyr-MjaΔU RPR compared to the wildtype, and this defect was partially ameliorated upon addition of either RPP pair. The catalytic defect in the archaeal mutant RPR mirrors that reported in a bacterial RPR and highlights a parallel in their active sites. Furthermore, an N-terminal deletion mutant of Pyrococcus furiosus (Pfu) RPP29 that is defective in assembling with its binary partner RPP21, as assessed by isothermal titration calorimetry and NMR spectroscopy, is functional when reconstituted with the cognate Pfu RPR. Collectively, these results indicate that archaeal RPPs are able to compensate for structural defects in their cognate RPR and vice-versa, and provide striking examples of the cooperative subunit interactions critical for driving archaeal RNase P towards its functional conformation. (236 words)
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在古细胞RNase P中解剖蛋白质亚基（一种催化核糖核蛋白复合物）中的功能合作。
影响因子：
14.9
作者：
Chen WY;Pulukkunat DK;Cho IM;Tsai HY;Gopalan V
通讯作者：
Gopalan V
影响因子：
2.9
作者：
Crary, SM;Niranjanakumari, S;Fierke, CA
通讯作者：
Fierke, CA
影响因子：
4.5
作者：
Jarrous, N;Reiner, R;Altman, S
通讯作者：
Altman, S
影响因子：
11.4
作者：
Christian, EL;Kaye, NM;Harris, ME
通讯作者：
Harris, ME
影响因子：
2.9
作者：
Amero, Carlos D.;Boomershine, William P.;Xu, Yiren;Foster, Mark
通讯作者：
Foster, Mark