Rhodius V A, Busby S J
School of Biochemistry, The University of Birmingham, Birmingham, B15 2TT, UK.
Curr Opin Microbiol. 1998 Apr;1(2):152-9. doi: 10.1016/s1369-5274(98)80005-2.
Most bacterial transcription activators function by making direct contact with RNA polymerase at target promoters. Some activators contact the carboxy-terminal domain of the RNA polymerase alpha subunit, some contact region 4 of the sigma70 subunit, whilst others interact with other contact sites. A number of activators are ambidextrous and can, apparently simultaneously, contact more than one target site on RNA polymerase. Expression from many promoters is co-dependent on two or more activators. There are several different mechanisms for coupling promoter activity to more than one activator: in one such mechanism, the different activators make independent contacts with different target sites on RNA polymerase.
大多数细菌转录激活因子通过在目标启动子处与RNA聚合酶直接接触发挥作用。一些激活因子与RNA聚合酶α亚基的羧基末端结构域接触，一些与σ70亚基的区域4接触，而其他一些则与其他接触位点相互作用。许多激活因子具有双功能，显然可以同时与RNA聚合酶上的多个靶位点接触。许多启动子的表达共同依赖于两种或更多种激活因子。将启动子活性与一种以上激活因子偶联有几种不同的机制：在一种这样的机制中，不同的激活因子与RNA聚合酶上不同的靶位点进行独立接触。
