Kajitani M, Ishihama A
Nucleic Acids Res. 1983 Jun 25;11(12):3873-88. doi: 10.1093/nar/11.12.3873.
Using the in vitro mixed transcription system (Kajitani, M. and Ishihama, A. (1983) Nucleic Acids Res. 11, 671-686), we determined the two parameters of the promoter strength, i.e., the rate of open complex formation between RNA polymerase and promoter, and the saturation level of the open complex formation at equilibrium, for the promoters of ribosomal RNA (rrnE), ribosomal protein S1 (rpsA) and recA protein (recA) operons from Escherichia coli. Taken together with the previous determinations for lactose (lac(UV5)), tryptophan (trp) and ribosomal protein L10 (rp1J) operons, these studies revealed that the relative promoter strengths with respect to the kinetic parameter are 200, 70, 50, 40, 30, 20 and 2% of the reference promoter lacP(UV5) for recAp, rp1Jp, rpsAp3, trpP, rpsAp1, rrnEp1 and rrnEp2, respectively, under our standard reaction conditions (50 mM NaCl and 37 degrees C); and those with respect to the thermodynamic parameter are 70, 35, 20, 10, 10, 10 and 5% the level of lacP(UV5) for rrnEp2, trpP, rpsAp3, rp1Jp, rpsAp1, rrnEp1 and recAp, respectively. The order of the promoter strength, however, changes with variation of the salt concentration or reaction temperature.
利用体外混合转录系统（Kajitani, M.和Ishihama, A.（1983年）《核酸研究》11卷，671 - 686页），我们测定了来自大肠杆菌的核糖体RNA（rrnE）、核糖体蛋白S1（rpsA）和recA蛋白（recA）操纵子启动子的两个启动子强度参数，即RNA聚合酶与启动子之间开放复合物形成的速率，以及平衡时开放复合物形成的饱和水平。结合之前对乳糖（lac(UV5)）、色氨酸（trp）和核糖体蛋白L10（rp1J）操纵子的测定，这些研究表明，在我们的标准反应条件（50 mM氯化钠和37摄氏度）下，相对于动力学参数，recAp、rp1Jp、rpsAp3、trpP、rpsAp1、rrnEp1和rrnEp2启动子的相对启动子强度分别为参考启动子lacP(UV5)的200%、70%、50%、40%、30%、20%和2%；相对于热力学参数，rrnEp2、trpP、rpsAp3、rp1Jp、rpsAp1、rrnEp1和recAp启动子的相对启动子强度分别为lacP(UV5)水平的70%、35%、20%、10%、10%、10%和5%。然而，启动子强度的顺序会随盐浓度或反应温度的变化而改变。
