Nonet M L, Marvel C C, Tolan D R
J Biol Chem. 1987 Sep 5;262(25):12209-17.
A 9.7-kilobase pair segment of the Escherichia coli chromosome spanning the hisT and purF loci has been characterized. Six genes were identified in this region by complete DNA sequence analysis, in vivo expression in maxicells, and RNA transcript analysis. S1 nuclease analysis has demonstrated that some of these genes are part of the hisT or purF operons. Two of the newly identified genes, dedA and dedB, were localized immediately downstream of hisT in the hisT operon. Two other genes, denoted dedC and dedD, have been localized between the hisT and purF operons. The other two genes, dedE and dedF flank the purF gene. dedE has been previously described as the first gene in the purF operon (Makaroff, C.A., and Zalkin, H. (1985) J. Biol. Chem. 260, 10378-10387). dedF was localized downstream from purF and is part of the purF operon. In addition, dedF is homologous to the ubiX gene of Salmonella typhimurium. Adjacent to dedF is the E. coli homologue of the S. typhimurium argT locus encoding the lysine/arginine/ornithine-binding protein. All of the genes in this region of the chromosome were found to be transcribed in a counter-clockwise direction on the E. coli map which revises the direction of purF transcription.
对大肠杆菌染色体上跨越hisT和purF基因座的一段9.7千碱基对的片段进行了表征。通过完整的DNA序列分析、在大细胞中的体内表达以及RNA转录本分析，在该区域鉴定出六个基因。S1核酸酶分析表明，其中一些基因是hisT或purF操纵子的一部分。新鉴定的两个基因dedA和dedB位于hisT操纵子中hisT的紧邻下游。另外两个基因dedC和dedD位于hisT和purF操纵子之间。另外两个基因dedE和dedF位于purF基因两侧。dedE先前已被描述为purF操纵子中的第一个基因（马卡罗夫，C.A.，和扎尔金，H.（1985年）《生物化学杂志》260，10378 - 10387）。dedF位于purF下游，是purF操纵子的一部分。此外，dedF与鼠伤寒沙门氏菌的ubiX基因同源。dedF旁边是编码赖氨酸/精氨酸/鸟氨酸结合蛋白的鼠伤寒沙门氏菌argT基因座的大肠杆菌同源物。发现染色体该区域的所有基因在大肠杆菌图谱上以逆时针方向转录，这修正了purF的转录方向。
