苯丙氨酰-tRNA合成酶的进化与结构域丢失

基因的复制、融合以及基因的水平转移是许多蛋白质包括氨酰 tRNA合成酶 (aminoacyl tRNAsynthetase ,AARS)进化过程中的常见事件。然而作者研究的结果显示 ,苯丙氨酰 tRNA合成酶 (phenylalanyl tRNAsynthetase,PheRS)的进化主要表现为一些结构域的丢失 ;并且这种结构域的丢失不影响PheRS的功能或活性。通常在生物从细菌到真核生物的进化过程中 ,其基因组的大小和基因的数目都有所增加 ,然而有趣的是 ,真核生物中PheRS的结构域类型和数目都明显少于细菌的PheRS。PheRS通过结构域的丢失而进化的现象 ,似乎与某些AARS功能由多重专一性向单一专一性的演化有着“异曲同工”之妙。

Evolution of Phenylalanyl-tRNA Synthetase by Domain Losing

The gene duplication, fusion and horizontal transfer are the frequent events during evolution of many proteins, including the aminoacyl-tRNA synthetases (AARSs). However, in this work, it was shown that the main event during evolution of phenylalanyl-tRNA synthetase (PheRS) is a domain loss, and the function/activity of PheRS is not affected by domain losing. Generally, the size of genome and number of genes are increased during evolution from bacteria to eukaryote, but the interesting thing is that the type and number of PheRS domains in eukaryotae are obviously less than those in bacteria. The evolution of PheRS by domain losing seems to be related to the functional evolution of some AARSs from the multiple specificities to the single specificity.