Zhu Yanglong, Stribinskis Vilius, Ramos Kenneth S, Li Yong
Department of Biochemistry and Molecular Biology, and Center for Genetics and Molecular Medicine, School of Medicine, University of Louisville, Kentucky 40202, USA.
RNA. 2006 May;12(5):699-706. doi: 10.1261/rna.2284906. Epub 2006 Mar 15.
RNase MRP is a eukaryote-specific endoribonuclease that generates RNA primers for mitochondrial DNA replication and processes precursor rRNA. RNase P is a ubiquitous endoribonuclease that cleaves precursor tRNA transcripts to produce their mature 5' termini. We found extensive sequence homology of catalytic domains and specificity domains between their RNA subunits in many organisms. In Candida glabrata, the internal loop of helix P3 is 100% conserved between MRP and P RNAs. The helix P8 of MRP RNA from microsporidia Encephalitozoon cuniculi is identical to that of P RNA. Sequence homology can be widely spread over the whole molecule of MRP RNA and P RNA, such as those from Dictyostelium discoideum. These conserved nucleotides between the MRP and P RNAs strongly support the hypothesis that the MRP RNA is derived from the P RNA molecule in early eukaryote evolution.
核糖核酸酶MRP是一种真核生物特有的内切核糖核酸酶，可生成用于线粒体DNA复制的RNA引物并加工前体核糖体RNA。核糖核酸酶P是一种普遍存在的内切核糖核酸酶，可切割前体tRNA转录本以产生其成熟的5'末端。我们发现，在许多生物体中，它们的RNA亚基之间的催化结构域和特异性结构域存在广泛的序列同源性。在光滑念珠菌中，螺旋P3的内环在MRP和P RNA之间100%保守。来自微小孢子虫兔脑炎微孢子虫的MRP RNA的螺旋P8与P RNA的螺旋P8相同。序列同源性可以广泛分布在MRP RNA和P RNA的整个分子上，例如来自盘基网柄菌的那些分子。MRP RNA和P RNA之间的这些保守核苷酸有力地支持了这样一种假说，即MRP RNA在早期真核生物进化中源自P RNA分子。
