Lee C Y, Meighen E A
Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
Biochem Biophys Res Commun. 1992 Jul 31;186(2):690-7. doi: 10.1016/0006-291x(92)90802-r.
Three open reading frames (ORFs) have been found in the region downstream of the luxG gene in the Photobacterium leiognathi lux operon. These genes (ORF I, II, and III) are not only closely linked to the lux operon and transcribed in the same direction but also show the same organization and code for proteins homologous in sequence to the gene products of ribB, ribA, and ribH of Bacillus subtilis, respectively. The Photobacterium leiognathi gene (ORF II) corresponding to ribA was expressed in Escherichia coli in the bacteriophage T7 promoter-RNA polymerase system and a 40 kDa 35S-labeled polypeptide has been detected on SDS-PAGE. Expression of DNA extending from luxBEG to ORF II inserted between a strong promoter and a reporter gene and transferred by conjugation into Vibrio harveyi did not affect the expression of the reporter gene. The results provide evidence that neither promoter nor terminator sites were present in the DNA between the luxG and ORF II indicating that these genes might be part of the lux operon.
在鱼发光杆菌lux操纵子中，luxG基因下游区域发现了三个开放阅读框（ORF）。这些基因（ORF I、II和III）不仅与lux操纵子紧密相连且转录方向相同，还具有相同的组织形式，并且分别编码与枯草芽孢杆菌ribB、ribA和ribH基因产物序列同源的蛋白质。对应于ribA的鱼发光杆菌基因（ORF II）在噬菌体T7启动子 - RNA聚合酶系统中于大肠杆菌中表达，并且在SDS - PAGE上检测到了一条40 kDa的35S标记多肽。从luxBEG延伸至ORF II的DNA在插入强启动子和报告基因之间后通过接合转移到哈维弧菌中，并未影响报告基因的表达。结果表明，luxG和ORF II之间的DNA中不存在启动子和终止子位点，这表明这些基因可能是lux操纵子的一部分。
