Inhibition Of Millet Wine Process In Fission Yeast Expression Coding Trna3 'end Processing Enzyme Gene Trz2 Toxicity Screening

As an adapter molecule between nucleonic and proteins, tRNA has a central role in biology.The3’CCA triplet of tRNA is a prerequisite for tRNA aminoacylation. But in eukaryotes, many eubacteria, and some archaea their tRNA genes not encode CCA, endonuclease tRNase Z catalyzes the generation of the mature3’end of tRNA precursors through specific endonucleolytic cleavage and providing the substrate for CCA addition by tRNA nucleotidyltransferase. tRNase Z enzymes belong to the superfamily of metallo-β-lactamases (MBL).This superfamily contains five highly conserved motifs including motif Ⅱ also called histidine motif (HxHxDH, x is any hydrophobic residues), a characteristic of the MBL superfamily. These are highly conserved in active members of the superfamily and participate in metal coordination and the hydrolysis reaction.tRNase Z is present in a short form (tRNase ZS) and a long form (tRNase ZL). The human tRNase ZL gene, ELAC2was initially found as a prostate cancer susceptibility gene. Schizosaccharomyces pombe contains two tRNase ZL genes, designated sptrzl+and sptrz2+. We certificated that the two genes both were essential genes and we showed that the localization and the function of the gene sptrzl+in our lab,which showed that the function of the gene sptrz2+. S. pombe was used as a model organism to investigate the functions of its tRNase Z (SpTrz2p) in this study, for promoting the understanding of the disease which caused by the3-end processing defect of pre-tRNA. The major findings were listed as follows:1. High-level overexpression of sptrzl+had no detectable phenotypes. In contrast, strong overexpression of sptrz2+was lethal in wild-type cells and results in morphological abnormalities, including swollen and round cells, demonstrating that the correct expression level of sptrz2+was critical.2. We introduced mutations on the conserved motif Ⅱ (HxHxDH) using over-lap PCR-based mutagenesis method,and we found it the same to the wild-type. It showed that the death strong overexpression of sptrz2+had no connect with the metal coordination and the hydrolysis of the histidine motif.3.Scaning the cDNA library of fission yeast, which called SPLE1, We found some candidates.Pdal, actl and gas2seemed interact with sptrz2. However, We confirmed that there was no interaction between these candidates and the SpTrz2p protein.