Guarente L P, Beckwith J
Proc Natl Acad Sci U S A. 1978 Jan;75(1):294-7. doi: 10.1073/pnas.75.1.294.
We have isolated a rifampicin-resistant mutant of Escherichia coli RNA polymerase that restores transcription termination in strains with a defective rho protein. In such strains, the mutant RNA polymerase terminates transcription at normally rho-dependent sites at the end of the trp operon, in bacteriophage lambda, and within the lac operon. In addition, a strain with this mutant RNA polymerase remains viable with an amber mutation in rho, whereas a strain with wild-type RNA polymerase does not. These results suggest that the mutant RNA polymerase can terminate transcription at normally rho-dependent sites in the absence of rho.
我们分离出了一株大肠杆菌RNA聚合酶的利福平抗性突变体，它能在rho蛋白缺陷的菌株中恢复转录终止。在这类菌株中，突变的RNA聚合酶能在色氨酸操纵子末端、噬菌体λ以及乳糖操纵子内正常依赖rho的位点终止转录。此外，携带这种突变RNA聚合酶的菌株在rho基因发生琥珀突变的情况下仍能存活，而携带野生型RNA聚合酶的菌株则不能。这些结果表明，突变的RNA聚合酶在没有rho的情况下能够在正常依赖rho的位点终止转录。
