Saint-Girons I, Duchange N, Cohen G N, Zakin M M
J Biol Chem. 1984 Nov 25;259(22):14282-5.
The nucleotide sequence of the Escherichia coli metJ regulatory gene (312 nucleotides) has been determined as well as that of two mutations located within the gene. Analysis of the sequence downstream from the metJ gene has revealed inverted repeats homologous to several intercistronic regions, also reported to occur between operons. A hybrid protein that contains the 55 first amino acid residues of the metJ protein substituting for the 8 amino acid residues at the NH2 terminus of beta-galactosidase was produced by gene fusion. The hybrid protein retaining beta-galactosidase activity was purified. Its amino-terminal sequence was determined and this allowed us to locate the translational start codon of the metJ gene. Evidence was provided for autoregulation by repression of the metJ gene. By sequencing upstream from metJ, the region situated between the metJ and metB genes was found to contain putative operator structures that we propose to call "Met boxes."
已确定大肠杆菌metJ调控基因的核苷酸序列（312个核苷酸）以及该基因内两个突变的核苷酸序列。对metJ基因下游序列的分析揭示了与几个基因间区域同源的反向重复序列，这些区域也被报道存在于操纵子之间。通过基因融合产生了一种杂合蛋白，该蛋白包含metJ蛋白的前55个氨基酸残基，取代了β-半乳糖苷酶NH2末端的8个氨基酸残基。保留β-半乳糖苷酶活性的杂合蛋白被纯化。测定了其氨基末端序列，这使我们能够定位metJ基因的翻译起始密码子。有证据表明metJ基因通过阻遏进行自我调节。通过对metJ上游进行测序，发现位于metJ和metB基因之间的区域包含假定的操纵子结构，我们提议将其称为“Met框”。
