Gralla J D
Department of Chemistry and Biochemistry, University of California, Los Angeles 90095-1569, USA.
Curr Opin Genet Dev. 1996 Oct;6(5):526-30. doi: 10.1016/s0959-437x(96)80079-7.
There is no organism in which transcription initiation is better understood than Escherichia coli. Recent studies using genetics, biochemistry and structure analysis have revealed how RNA polymerase interactions at promoters are regulated. Prominent examples include the recruitment of polymerase by activators touching its alpha and sigma subunits; which subunit is touched depends on which activator is used and where it binds the DNA. The less-common cases centering on enhancer-dependent transcription use an entirely different mechanism, involving either DNA looping or tracking.
没有哪种生物的转录起始比大肠杆菌得到了更好的理解。最近利用遗传学、生物化学和结构分析进行的研究揭示了RNA聚合酶在启动子处的相互作用是如何被调控的。突出的例子包括激活剂通过接触其α和σ亚基来招募聚合酶；被接触的亚基取决于所使用的激活剂及其与DNA的结合位置。以增强子依赖性转录为中心的不太常见的情况则使用完全不同的机制，涉及DNA环化或追踪。
