Department of Frontier Bioscience and Micro-Nano Technology Research Center, Hosei University, Koganei, Tokyo 184-8584, Japan.
Proc Jpn Acad Ser B Phys Biol Sci. 2012;88(9):485-508. doi: 10.2183/pjab.88.485.
After determination of the whole genome sequence, the research frontier of bacterial molecular genetics has shifted to reveal the genome regulation under stressful conditions in nature. The gene selectivity of RNA polymerase is modulated after interaction with two groups of regulatory proteins, 7 sigma factors and 300 transcription factors. For identification of regulation targets of transcription factors in Escherichia coli, we have developed Genomic SELEX system and subjected to screening the binding sites of these factors on the genome. The number of regulation targets by a single transcription factor was more than those hitherto recognized, ranging up to hundreds of promoters. The number of transcription factors involved in regulation of a single promoter also increased to as many as 30 regulators. The multi-target transcription factors and the multi-factor promoters were assembled into complex networks of transcription regulation. The most complex network was identified in the regulation cascades of transcription of two master regulators for planktonic growth and biofilm formation.
在确定整个基因组序列后，细菌分子遗传学的研究前沿已经转移到揭示自然应激条件下的基因组调控。RNA 聚合酶与两组调节蛋白（7 个σ因子和 300 个转录因子）相互作用后，其基因选择性得到调节。为了鉴定大肠杆菌中转录因子的调控靶点，我们开发了基因组 SELEX 系统，并对这些因子在基因组上的结合位点进行了筛选。单个转录因子的调控靶点数量超过了以往的认识，多达数百个启动子。参与单个启动子调控的转录因子数量也增加到多达 30 个调节剂。多靶点转录因子和多因子启动子被组装成转录调控的复杂网络。在浮游生长和生物膜形成的两个主调控因子的转录调控级联中，发现了最复杂的网络。
