National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA.
Genome Biol Evol. 2013;5(3):494-503. doi: 10.1093/gbe/evt024.
The sequences of different proteins evolve at different rates. The relative evolutionary rate (ER) of a single protein also changes over evolutionary time. The cause of this ER fluctuation remains uncertain, and study of this phenomenon may shed light on protein evolution more broadly. We have characterized ER fluctuation in mammals and Drosophila. We found little correlation between the amount of rate variation observed for a protein and such factors as its expression level or phylogenetic distribution. Perhaps more surprisingly, we found little correlation between our measure of rate variation and ER itself. We also investigated the extent to which the ERs of different domains of a protein vary independently. We found that rates of different domains do tend to vary together. In fact, rates at positions in different domains are coupled just as strongly as rates at equally distant positions in the same domain. These findings provide clues to the protein evolutionary process.
不同蛋白质的序列以不同的速度进化。单个蛋白质的相对进化率（ER）也会随着进化时间而变化。这种 ER 波动的原因尚不确定，对这一现象的研究可能会更广泛地揭示蛋白质进化的奥秘。我们已经对哺乳动物和果蝇中的 ER 波动进行了特征描述。我们发现，观察到的蛋白质的速率变化量与表达水平或系统发育分布等因素之间几乎没有相关性。也许更令人惊讶的是，我们发现我们的速率变化测量值与 ER 本身之间几乎没有相关性。我们还研究了蛋白质不同结构域的 ER 变化是否独立。我们发现，不同结构域的速率确实倾向于一起变化。事实上，不同结构域中位置的速率与同一结构域中相同距离位置的速率一样紧密地耦合。这些发现为蛋白质进化过程提供了线索。
