An evolutionary 'intermediate state' of mitochondrial translation systems found in Trichinella species of parasitic nematodes:: co-evolution of tRNA and EF-Tu
An evolutionary 'intermediate state' of mitochondrial translation systems found in Trichinella species of parasitic nematodes:: co-evolution of tRNA and EF-Tu
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DOI：
10.1093/nar/gkl526
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发表时间：
2006-10-01
影响因子：
14.9
通讯作者：
Ohtsuki, Takashi
中科院分区：
文献类型：
--
作者：
Arita, Masashi;Suematsu, Takuma;Ohtsuki, Takashi
EF-Tu在翻译系统中将氨酰-tRNA递送到核糖体。然而，在一些动物线粒体tRNA中发现的不寻常的截短似乎阻止了经典EF-Tu的识别。我们以前表明，染色质壁线虫有两个不同的EF-Tus，其中之一（EF-Tu 1）只结合T-臂氨酰-tRNA和其他（EF-Tu 2）结合D-臂丝氨酸-tRNA。两种EF-Tus都不能与典型的三叶草型tRNA结合。在这项研究中，通过分析的翻译系统的enoplean线虫旋毛虫物种，我们解决如何EF-Tus和tRNA已经从典型的结构向那些chromodorean翻译系统的演变。旋毛虫线粒体具有三种类型的tRNA：三叶草tRNA，其不存在于染色质线虫线粒体中; T-无臂tRNA;和D-无臂tRNA。我们发现两个线粒体EF-Tu物种，EF-Tu 1和EF-Tu 2，在旋毛虫布氏。布氏锥虫EF-Tu 2与秀丽隐杆线虫EF-Tu 2一样，只能与无D臂的Ser-tRNA结合。然而，与秀丽隐杆线虫EF-Tu 1的情况相反，布氏锥虫EF-Tu 1与旋毛虫线粒体中存在的所有三种类型的tRNA结合。这些结果表明，旋毛虫线粒体翻译系统，特别是EF-Tu 1的tRNA结合特异性，可能是一个中间状态之间的典型系统和染色质线虫线粒体系统。
EF-Tu delivers aminoacyl-tRNAs to ribosomes in the translation system. However, unusual truncations found in some animal mitochondrial tRNAs seem to prevent recognition by a canonical EF-Tu. We showed previously that the chromadorean nematode has two distinct EF-Tus, one of which (EF-Tu1) binds only to T-armless aminoacyl-tRNAs and the other (EF-Tu2) binds to D-armless Ser-tRNAs. Neither of the EF-Tus can bind to canonical cloverleaf tRNAs. In this study, by analyzing the translation system of enoplean nematode Trichinella species, we address how EF-Tus and tRNAs have evolved from the canonical structures toward those of the chromadorean translation system. Trichinella mitochondria possess three types of tRNAs: cloverleaf tRNAs, which do not exist in chromadorean nematode mitochondria; T-armless tRNAs; and D-armless tRNAs. We found two mitochondrial EF-Tu species, EF-Tu1 and EF-Tu2, in Trichinella britovi. T.britovi EF-Tu2 could bind to only D-armless Ser-tRNA, as Caenorhabditis elegans EF-Tu2 does. In contrast to the case of C.elegans EF-Tu1, however, T.britovi EF-Tu1 bound to all three types of tRNA present in Trichinella mitochondria. These results suggest that Trichinella mitochondrial translation system, and particularly the tRNA-binding specificity of EF-Tu1, could be an intermediate state between the canonical system and the chromadorean nematode mitochondrial system.