Houman F, Rho S B, Zhang J, Shen X, Wang C C, Schimmel P, Martinis S A
Department of Biology and Biochemistry, University of Houston, 3201 Cullen, Houston, TX 77204-5513, USA.
Proc Natl Acad Sci U S A. 2000 Dec 5;97(25):13743-8. doi: 10.1073/pnas.240465597.
Mitochondrial leucyl-tRNA synthetase (LeuRS) in the yeast Saccharomyces cerevisiae provides two essential functions. In addition to aminoacylation, LeuRS functions in RNA splicing. The details of how it came to act in splicing are not known. Here we show that Mycobacterium tuberculosis and human mitochondrial LeuRSs can substitute in splicing for the S. cerevisiae mitochondrial LeuRS. Mutations of yeast mitochondrial LeuRS that had previously been shown to abolish splicing activity also eliminate splicing by the M. tuberculosis enzyme. These results suggest the role of LeuRS in splicing in yeast mitochondria results from features of the enzyme that are broadly conserved in evolution. These features are not likely to be designed for splicing per se, but instead have been adopted in yeast for that purpose.
酿酒酵母中的线粒体亮氨酰 - tRNA合成酶(LeuRS)具有两种重要功能。除了氨基酰化作用外,LeuRS还参与RNA剪接。其如何开始参与剪接的具体细节尚不清楚。在此我们表明,结核分枝杆菌和人类线粒体LeuRS可以替代酿酒酵母线粒体LeuRS进行剪接。先前已证明可消除剪接活性的酵母线粒体LeuRS突变,也会消除结核分枝杆菌酶的剪接作用。这些结果表明,LeuRS在酵母线粒体剪接中的作用源于该酶在进化中广泛保守的特征。这些特征本身不太可能是为剪接而设计的,而是在酵母中被用于此目的。