Tsukagoshi N, Furukawa M, Nagaba H, Kirita N, Tsuboi A, Udaka S
Department of Food Science and Technology, Faculty of Agriculture, Nagoya University, Japan.
Gene. 1989 Dec 14;84(2):319-27. doi: 10.1016/0378-1119(89)90506-4.
Complementary and genomic DNAs encoding Aspergillus oryzae Taka-amylase A (Taa) were cloned and sequenced. The coding sequence of the cDNA comprised the signal peptide [21 amino acids (aa)] and mature Taa (478 aa). The deduced aa sequence agrees well with the published aa sequence, except for one insertion, one deletion and ten aa substitutions. These differences might be due to the difference in the strains used. Sequence comparison of the cDNA and genomic DNA indicates the presence of eight introns ranging in size from 55 to 86 bp. Southern-blot analysis showed the presence of at least two Taa genes, and the second gene (Taa-G2) was isolated. All the intron/exon junctions follow the 'GT-AG' rule, except for intron I of the first gene (Taa-G1). The 5'-noncoding region was well conserved among the genomic genes and contained sequences similar to 'CAAT' and 'TATA' boxes at nucleotides -121 and -31, counted from the transcription start point, respectively. The 3'-noncoding regions, however, differed significantly from each other. Taa-G2 contains a sequence identical to that of several independent cDNA clones, suggesting that it may be the major transcribed gene in A. oryzae.
编码米曲霉Taka淀粉酶A（Taa）的互补DNA和基因组DNA被克隆并测序。cDNA的编码序列包括信号肽（21个氨基酸）和成熟Taa（478个氨基酸）。推导的氨基酸序列与已发表的氨基酸序列吻合良好，但存在一个插入、一个缺失和十个氨基酸替换。这些差异可能是由于所用菌株的不同。cDNA与基因组DNA的序列比较表明存在八个内含子，大小在55至86碱基对之间。Southern杂交分析显示至少存在两个Taa基因，并分离出了第二个基因（Taa-G2）。除了第一个基因（Taa-G1）的内含子I外，所有内含子/外显子边界均遵循“GT-AG”规则。5'-非编码区在基因组基因中保守性良好，分别从转录起始点计数，在核苷酸-121和-31处含有类似于“CAAT”和“TATA”框的序列。然而，3'-非编码区彼此差异显著。Taa-G2包含与几个独立cDNA克隆相同的序列，表明它可能是米曲霉中的主要转录基因。
