Hoshiko S, Makabe O, Nojiri C, Katsumata K, Satoh E, Nagaoka K
J Bacteriol. 1987 Mar;169(3):1029-36. doi: 10.1128/jb.169.3.1029-1036.1987.
We have isolated and sequenced a gene (amy) coding for alpha-amylase (EC 3.2.1.1.) from the Streptomyces hygroscopicus genome (H. Hidaka, Y. Koaze, K. Yoshida, T. Niwa, T. Shomura, and T. Niida, Die Stärke 26:413-416, 1974). Amylase was purified to obtain amino acid sequence information which was used to synthesize oligonucleotide probes. amy-containing Escherichia coli cosmids identified by hybridization did not express amylase activity. Subcloning experiments indicated that amy could be expressed from the lac promoter in E. coli or from its own promoter in S. lividans. The amy nucleotide sequence indicated that it coded for a protein of 52 kilodaltons (478 amino acids). Secreted alpha-amylase contained amino- and carboxy-terminal as well as internal amino acid sequences which were consistent with the nucleotide sequence. The 30-residue leader sequence showed similarities to those found in other procaryotes. The DNA sequence 5' to the amy structural gene contained a sequence complementary to the 3'-terminal sequence of 16S rRNA of S. lividans (M. J. Bibb and S. N. Cohen, Mol. Gen. Genet. 187:265-277, 1982). The transcriptional start points of amy were determined by mung bean nuclease mapping, but the promoter of amy was not similar to the consensus sequence found in other procaryotes.
我们已经从吸水链霉菌基因组中分离并测序了一个编码α-淀粉酶（EC 3.2.1.1.）的基因（amy）（H. Hidaka、Y. Koaze、K. Yoshida、T. Niwa、T. Shomura和T. Niida，《淀粉》26:413 - 416，1974）。纯化淀粉酶以获得氨基酸序列信息，该信息用于合成寡核苷酸探针。通过杂交鉴定的含amy的大肠杆菌黏粒不表达淀粉酶活性。亚克隆实验表明，amy可以在大肠杆菌中从lac启动子表达，或者在变铅青链霉菌中从其自身启动子表达。amy核苷酸序列表明它编码一个52千道尔顿的蛋白质（478个氨基酸）。分泌的α-淀粉酶包含的氨基末端、羧基末端以及内部氨基酸序列与核苷酸序列一致。30个残基的前导序列与其他原核生物中的前导序列相似。amy结构基因5'端的DNA序列包含一个与变铅青链霉菌16S rRNA 3'末端序列互补的序列（M. J. Bibb和S. N. Cohen，《分子与普通遗传学》187:265 - 2T7，1982）。通过绿豆核酸酶图谱分析确定了amy的转录起始点，但amy的启动子与其他原核生物中发现的共有序列不相似。
