Ihara H, Sasaki T, Tsuboi A, Yamagata H, Tsukagoshi N, Udaka S
J Biochem. 1985 Jul;98(1):95-103. doi: 10.1093/oxfordjournals.jbchem.a135279.
The nucleotide sequence of a thermophilic, liquefying alpha-amylase gene cloned from B. stearothermophilus was determined. The NH2-terminal amino acid sequence analysis of the B. stearothermophilus alpha-amylase confirmed that the reading frame of the gene consisted of 1,644 base pairs (548 amino acids). The B. stearothermophilus alpha-amylase had a signal sequence of 34 amino acids, which was cleaved at exactly the same site in E. coli. The mature enzyme contained two cysteine residues, which might play an important role in maintenance of a stable protein conformation. Comparison of the amino acid sequence inferred from the B. stearothermophilus alpha-amylase gene with those inferred from other bacterial liquefying alpha-amylase genes and with the amino acid sequences of eukaryotic alpha-amylases showed three homologous sequences in the enzymatically functional regions.
测定了从嗜热脂肪芽孢杆菌克隆的嗜热液化α-淀粉酶基因的核苷酸序列。嗜热脂肪芽孢杆菌α-淀粉酶的氨基末端氨基酸序列分析证实，该基因的阅读框由1644个碱基对组成（548个氨基酸）。嗜热脂肪芽孢杆菌α-淀粉酶有一个34个氨基酸的信号序列，在大肠杆菌中于完全相同的位点被切割。成熟酶含有两个半胱氨酸残基，这可能在维持稳定的蛋白质构象中起重要作用。将嗜热脂肪芽孢杆菌α-淀粉酶基因推导的氨基酸序列与其他细菌液化α-淀粉酶基因推导的氨基酸序列以及真核α-淀粉酶的氨基酸序列进行比较，发现在酶功能区有三个同源序列。
