RNase P enzymes Divergent scaffolds for a conserved biological reaction
RNase P enzymes Divergent scaffolds for a conserved biological reaction
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DOI：
10.4161/rna.24513
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发表时间：
2013-06-01
期刊：
影响因子：
4.1
通讯作者：
Engelke, David R.
中科院分区：
文献类型：
--
作者：
Howard, Michael J.;Liu, Xin;Engelke, David R.
核糖核酸酶P （RNase P）催化前体trna （pre-tRNA）的5端成熟，在生命的所有领域都是保守的。然而，从细菌到古细菌和真核生物，RNase P的组成各不相同，使RNase P成为最多样化的酶之一。大多数已知的RNase P酶含有一个大的催化RNA亚基，与1到10个蛋白质结合。最近，在许多高等真核生物的线粒体和叶绿体中发现了一种仅蛋白形式的RNase P。这种蛋白质核糖核酸酶（PRORP）代表了一类新的金属核酸酶。在这里，我们讨论了我们最近从拟南芥中获得的prop1的晶体结构，并推测了催化RNA被蛋白质催化剂取代的原因。基于对核糖核蛋白（RNP）和PRORP酶催化效率的分析，我们得出结论，对更高催化效率的需求很可能不是用蛋白质催化剂替代RNA背后的驱动力。基于蛋白质的RNase P的出现更可能反映了生物系统日益复杂，包括导入细胞器的困难和细胞器rna易被切割。
Ribonuclease P (RNase P) catalyzes the maturation of the 5 end of precursor-tRNAs (pre-tRNA) and is conserved in all domains of life. However, the composition of RNase P varies from bacteria to archaea and eukarya, making RNase P one of the most diverse enzymes characterized. Most known RNase P enzymes contain a large catalytic RNA subunit that associates with one to 10 proteins. Recently, a protein-only form of RNase P was discovered in mitochondria and chloroplasts of many higher eukaryotes. This proteinaceous RNase P (PRORP) represents a new class of metallonucleases. Here we discuss our recent crystal structure of PRORP1 from Arabidopsis thaliana and speculate on the reasons for the replacement of catalytic RNA by a protein catalyst. We conclude, based on an analysis of the catalytic efficiencies of ribonucleoprotein (RNP) and PRORP enzymes, that the need for greater catalytic efficiency is most likely not the driving force behind the replacement of the RNA with a protein catalyst. The emergence of a protein-based RNase P more likely reflects the increasing complexity of the biological system, including difficulties in importation into organelles and vulnerability of organellar RNAs to cleavage.