Analysis of cellular function of tRNase Z in Saccharomyces cerevisiae

在真核生物中，核糖核酸酶tRNase Z通过识别位点的特异性内切作用催化tRNA前体的成熟3‘端的产生。芽生酵母具有单一的长tRNase Z，重组酵母tRNase Z蛋白在体外具有前体tRNA3‘-加工活性。酵母tRNase Z蛋白定位于细胞核，是生长所必需的。酵母tRNase Z的温度敏感(Ts)突变体表现出3‘-未处理的前tRNAs的积累。因此，我们的发现表明，sctRNase ZL可能是前tRNAs的3‘端处理所必需的。

Endoribonuclease tRNase Z catalyzes the generation of the mature 3' end of tRNA precursors through specific endonucleolytic cleavage at discriminator site in eukaryotic organisms. The budding yeast Saccharomyces cerevisiae has a single long form of tRNase Z. The recombinant yeast tRNase Z protein possesses precursor tRNA 3'-processing activity in vitro. The yeast tRNase Z protein localizes to the nucleus and is essential for growth. Temperature-sensitive(Ts) mutants of yeast tRNase Z exhibit the accumulation of 3′-unprocessed pre-tRNAs. Thus, our findings suggest that the sctRNase ZL may be required for the 3′end processing of pre-tRNAs.