【摘要】 木聚糖酶Ⅱ (XylanaseⅡ )是瑞氏木霉中两种主要的内切木聚糖酶之一 .序列分析显示其 1.1kb的启动子区含有多种丝状真菌转录因子结合位点 ,可受多种激活因子、抑制因子、增强子的转录调控 .以编码 β -葡糖苷酸酶(GUS)的E .coliuidA基因为报告基因 ,分别与木聚糖酶Ⅱ启动子及功能区 (- 312～ - 10 80 )缺失启动子融合 ,构建报告质粒pXIIPU与pXIIPΔEXU ,引入瑞氏木霉蛋白酶缺陷株TrichodermareeseiRutC30U4 .先后对转化子进行发酵实验 ,测定GUS活性 ,结果显示功能区 - 312～ - 10 80缺失后的启动子活性是原启动子活性的 19% .结果表明在缺失的木聚糖酶Ⅱ启动子 - 312～ - 10 80区仍存在调节转录活性的顺式作用元件 ,值得进一步研究 .更多还原

【Abstract】 Xylanase Ⅱ is one of the two most important endoxylanases in Trichoderma reesei . Therer are many potential binding sites for transcriptional factors in filamentous fungi located in the xylanase Ⅱ promoter,which suggest that the xyn2 promoter is subject to the transcriptional regulation by various activators,repressors,and enhancers. Fusing the reporter gene E. coli uidA gene with the xyn2 promoter and deletion (-312～ -1080) promoter respectively,resulted in pXIIPU and pXIIPΔEXU,which were introduced separately into T. reesei RutC30 U4,a protease-deficient strain. The GUS expression level reveals that the activity of the deletion (-312～ -1080) promoter was about 19% of that whole promoter. The results suggest that potential cis -acting regulatory elements existed in the -321～ -1080 region of xyn2 promoter and it is worth studying further.更多还原