EVOLUTION OF COMPENSATORY SUBSTITUTIONS THROUGH G.U INTERMEDIATE STATE IN DROSOPHILA RIBOSOMAL-RNA
EVOLUTION OF COMPENSATORY SUBSTITUTIONS THROUGH G.U INTERMEDIATE STATE IN DROSOPHILA RIBOSOMAL-RNA
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DOI：
10.1073/pnas.88.22.10032
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发表时间：
1991-11-01
影响因子：
11.1
通讯作者：
SOLIGNAC, M
中科院分区：
文献类型：
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作者：
ROUSSET, F;PELANDAKIS, M;SOLIGNAC, M
经常有人认为，在RNA螺旋结构中经常观察到的沃森-克里克碱基对补偿取代主要是通过稍微有害的G.U中间状态发生的。我们在一组82个相关的果蝇物种中对大rRNA亚基的D1和D2可变结构域进行了碱基替换。在所有发生G-C A-U补偿性碱基变化的地点，在一个或几个物种中观察到G.U对。由于这一主导过程意味着两个转换，它们在配对区域（92%）中的比率远远高于非配对区域（47%）。其他类型的补偿是罕见的，没有观察到中间状态。在一个物种中观察到的大多数G-U碱基对都不是轻微有害的。补偿性替代的进化速度接近于通过稍微有害或稍微有利的G.U对的补偿性替代的简单模型所预测的速度，尽管提出了一些例外。
It has often been suggested that the frequently observed Watson-Crick base-pair compensatory substitutions in RNA helical structures occur mainly through a slightly deleterious G.U intermediate state. We have scored base substitutions in a set of 82 related Drosophila species for the D1 and D2 variable domains of the large rRNA subunit. In all locations where a G-C A-U compensatory base change occurred, a G.U pair has been observed in one or several species. As this dominant process implies two transitions, their rate was far higher in paired regions (92 %) than in unpaired regions (47 %). The other types of compensation were rarer and no intermediate states were observed. Most of the G-U base pairs observed in a species are not slightly deleterious. The rate of evolution of compensatory substitution is close to that predicted by a simple model of compensatory substitution through slightly deleterious or slightly advantageous G.U pairs, although some exceptions are presented.