Phylogenetic-comparative analysis of the eukaryal ribonuclease P RNA
Phylogenetic-comparative analysis of the eukaryal ribonuclease P RNA
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DOI：
10.1017/s1355838200001461
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发表时间：
2000-12-01
期刊：
影响因子：
4.5
通讯作者：
Pace, NR
中科院分区：
文献类型：
--
作者：
Frank, DN;Adami, C;Pace, NR
核糖核酸酶P（RNase P）是核糖核蛋白酶，其从核糖体转移RNA切割5 '-前导序列。细菌和真核生物的RNase P RNA的根本区别在于，前者而不是后者能够在没有蛋白质的情况下在体外催化前tRNA成熟。这些功能差异的解释将有助于细菌和真核RNase P RNA结构的详细比较。然而，与细菌和古细菌同源物相比，真核RNase P RNA的结构仍然很差。因此，我们采用遗传学比较的方法来完善真核RNase P RNA的二级结构。为此，已经从代表Arxiozyma属、Clavispora属、Kluyveromyces属、Pichia属、Saccharomyces属、拟青霉属、Torulaspora属、Wickerhamia属和Zygosaccharomyces属的子囊菌属真菌物种中确定了20个新的RNase P RNA序列。这些序列和其他序列的系统发育比较分析完善了以前的真核RNase P RNA二级结构模型。序列保守和长度变异的模式完善了核心真核RNA结构的最小一致性模型。与细菌RNase P RNA相比，真核同源物缺乏被认为对底物结合和催化都至关重要的RNA结构元件。然而，真核RNA保留了细菌RNase P催化核心的主要特征。这表明真核RNA本质上仍然是核酶。
Ribonuclease P (RNase P) is the ribonucleoprotein enzyme that cleaves 5'-leader sequences from precursor-tRNAs. Bacterial and eukaryal RNase P RNAs differ fundamentally in that the former, but not the latter, are capable of catalyzing pre-tRNA maturation in vitro in the absence of proteins. An explanation of these functional differences will be assisted by a detailed comparison of bacterial and eukaryal RNase P RNA structures. However, the structures of eukaryal RNase P RNAs remain poorly characterized, compared to their bacterial and archaeal homologs. Hence, we have taken a phylogenetic-comparative approach to refine the secondary structures of eukaryal RNase P RNAs. To this end, 20 new RNase P RNA sequences have been determined from species of ascomycetous fungi representative of the genera Arxiozyma, Clavispora, Kluyveromyces, Pichia, Saccharomyces, Saccharomycopsis, Torulaspora, Wickerhamia, and Zygosaccharomyces. Phylogenetic-comparative analysis of these and other sequences refines previous eukaryal RNase P RNA secondary structure models. Patterns of sequence conservation and length variation refine the minimum-consensus model of the core eukaryal RNA structure. In comparison to bacterial RNase P RNAs, the eukaryal homologs lack RNA structural elements thought to be critical for both substrate binding and catalysis. Nonetheless, the eukaryal RNA retains the main features of the catalytic core of the bacterial RNase P. This indicates that the eukaryal RNA remains intrinsically a ribozyme.