瑞氏木霉EG Ⅰ 3‘—UTR对基因在酿酒酵母中表达的影响

将纤维素降解菌丝状真菌瑞氏木霉内切葡聚糖酶Ⅰ（EGⅠ）全长cDNA克隆于酿酒酵母H158中得到表达。重组酿酒酵母产生的EIⅠ的最适pH值为5．0，最适作用温度为50℃-60℃。EGⅠcDNA中的3‘- 非翻译区（3‘-UTR)序列的删除导致EGI基因在酵母菌中没有活性产物表达。通过RT－PCR技术检测EGⅠmRNA转录水平的结果表明，带有3‘-UTA的EGⅠcDNA在酿酒酵母中具有明显的转录产物生成，但删除3‘-UTR之后的EGⅠcDNA去检测不到转录产物。这说明EGⅠ的3‘-UTA对基因在酵母菌中的表达具有重要作用。

Effect of 3'-UTR of EG I from Trichoderma reesei on its gene expression in Saccharomyces cerevisiae]

Several industrial yeast are developed as ideal expression hosts for the production of the commercially useful proteins. The expression levels in yeast cells of the heterologous proteins are affected by the regulation factors of the genes themselves. The full-length cDNA coding for EG I from Trichoderma reesei, the cellulose-degrading filamentous fungus, was expressed in Saccharomyces cerevisiae H158. EG I produced by the recombinant S. cerevisiae exhibits maximal activity at 50 degrees C-60 degrees C, pH 5.0. It was observed that removal of the 3'-untranslated region (3'-UTR) from EG I cDNA resulted in no active EG I produced by recombinant yeast. RT-PCR analysis indicated that unlike the yeast cells harboring full-length EG I cDNA, there was no detectable EG I mRNA in the yeast cells harboring EG I cDNA without 3'-UTR. The data suggested that 3'-UTR is important for the expression of EG I in Saccharomyces cerevisiae.