Musso R E, de Crombrugghe B, Pastan I, Sklar J, Yot P, Weissman S
Proc Natl Acad Sci U S A. 1974 Dec;71(12):4940-4. doi: 10.1073/pnas.71.12.4940.
The 5'-terminal sequence of mRNA from the galactose operon of E. coli has been determined. gal RNA is synthesized in vitro by means of a kinetically controlled purified transcription system and is isolated by a two-step RNA.DNA hybridization scheme. The following sequence of the first 77 nucleotides has been deduced by analysis of oligonucleotides produced by digestion with T(1), pancreatic, and carboxymethylated pancreatic ribonucleases: ppA-U-A-C-C-A-U-A-A-G-C-C-U-A-A-U-G-G-A-G-C-G-A-A-U-U-A-U-G-A-G-A-G-U-U-C-U-G-G-U-U-A-C-C-G-G-U-G-G-U-A-G-C-G-G-U-U-A-C-A-U-U-G-G-A-A-G-U-C-A-U-A-C-C-U-G-U. Residues 27-77 correspond to the amino terminal 17 amino acids of UDPgalactose 4-epimerase (EC 5.1.3.2), the protein specified by the promoter-proximal structural gene of the operon. A self-complementary sequence occurs near the 5' terminus; 12 of 15 nucleotides between residues 4 and 18 are symmetrically located about position 11. The sequence of residues 22-33 closely resembles part of the lactose operator sequence reported previously [Gilbert, W. & Maxam, A. (1973) Proc. Nat. Acad. Sci. USA 70, 3581-3584].
已确定大肠杆菌半乳糖操纵子mRNA的5'末端序列。半乳糖RNA是通过动力学控制的纯化转录系统在体外合成的，并通过两步RNA-DNA杂交方案进行分离。通过分析用T(1)、胰核糖核酸酶和羧甲基化胰核糖核酸酶消化产生的寡核苷酸，推导出了前77个核苷酸的以下序列：ppA-U-A-C-C-A-U-A-A-G-C-C-U-A-A-U-G-G-A-G-C-G-A-A-U-U-A-U-G-A-G-A-G-U-U-C-U-G-G-U-U-A-C-C-G-G-U-G-G-U-A-G-C-G-G-U-U-A-C-A-U-U-G-G-A-A-G-U-C-A-U-A-C-C-U-G-U。第27至77位残基对应于UDP半乳糖4-表异构酶（EC 5.1.3.2）的氨基末端17个氨基酸，该酶是由操纵子启动子近端结构基因指定的蛋白质。在5'末端附近出现一个自我互补序列；第4至18位残基之间15个核苷酸中的12个围绕第11位对称定位。第22至33位残基的序列与先前报道的乳糖操纵基因序列的一部分非常相似[吉尔伯特，W.和马克萨姆，A.（1973年）美国国家科学院院刊70，3581-3584]。
