Minetoki T, Nunokawa Y, Gomi K, Kitamoto K, Kumagai C, Tamura G
General Research Laboratory, Ozeki Corp., 4-9, Imazu Dezaike-cho, Nishinomiya-shi, Hyogo 663, Japan.
Curr Genet. 1996 Nov;30(5):432-8. doi: 10.1007/s002940050153.
The nucleotide sequence of a 1.5-kb fragment of the promoter region of the Aspergillus oryzae agdA gene encoding alpha-glucosidase was determined. A comparison with the promoter regions of other Aspergillus amylase genes indicated that there are three highly conserved sequences, designated Regions I, II and III, located at -670 nt, -596 nt and -544 nt relative to the start codon, respectively. The function of these consensus sequences in the agdA promoter was investigated by deletion analysis of a promoter fusion with the Escherichia coli uidA gene, using the niaD homologous-transformation system. Deletion of the upstream half of Region III (IIIa; -544 to -529) resulted in a more than 90% reduction in GUS activity and abolished maltose induction, suggesting that Region IIIa is a functionally essential element for high-level expression and maltose induction. Deletion of Region I and the downstream half of Region III (IIIb; -521 to -511) resulted in a significant reduction in GUS activity, but did not affect maltose induction. This suggested that these two elements most likely contain sequences involved in efficient expression in cooperation with Region IIIa. In addition, deletion of a 340-bp region between Region IIIb and the putative TATA box resulted in a 2-fold increase in activity.
测定了米曲霉编码α-葡萄糖苷酶的agdA基因启动子区域1.5kb片段的核苷酸序列。与其他曲霉淀粉酶基因的启动子区域比较表明，存在三个高度保守的序列，分别命名为区域I、II和III，相对于起始密码子分别位于-670nt、-596nt和-544nt处。利用niaD同源转化系统，通过与大肠杆菌uidA基因的启动子融合进行缺失分析，研究了这些共有序列在agdA启动子中的功能。缺失区域III的上游一半（IIIa；-544至-529）导致GUS活性降低90%以上，并消除了麦芽糖诱导作用，表明区域IIIa是高水平表达和麦芽糖诱导的功能必需元件。缺失区域I和区域III的下游一半（IIIb；-521至-511）导致GUS活性显著降低，但不影响麦芽糖诱导。这表明这两个元件很可能包含与区域IIIa协同参与高效表达的序列。此外，缺失区域IIIb与假定的TATA框之间的340bp区域导致活性增加2倍。
