Pittard J
Department of Microbiology, University of Melbourne, Victoria, Australia.
Genes Cells. 1996 Aug;1(8):717-25. doi: 10.1111/j.1365-2443.1996.tb00012.x.
The TyrR Regulon of Escherichia coli comprises eight transcription units whose expression is modulated by the TyrR protein. This protein, which is normally a homodimer in solution, can self-associate to form a hexamer, bind with high affinity to specific DNA sequences (TyrR boxes) and interact with the alpha subunit of the RNA polymerase. These various reactions are influenced by the abundance of one or more of the aromatic amino acids, tyrosine, phenylalanine or tryptophan and by the specific location and sequence of the TyrR boxes associated with each transcription unit. This review describes how these activities can be combined in different ways to produce a variety of responses to varying levels of the three aromatic amino acids.
大肠杆菌的TyrR调节子由八个转录单元组成，其表达受TyrR蛋白调控。该蛋白在溶液中通常为同型二聚体，可自我缔合形成六聚体，与特定DNA序列（TyrR框）高亲和力结合并与RNA聚合酶的α亚基相互作用。这些不同反应受一种或多种芳香族氨基酸（酪氨酸、苯丙氨酸或色氨酸）的丰度以及与每个转录单元相关的TyrR框的特定位置和序列影响。本综述描述了这些活性如何以不同方式组合，以对三种芳香族氨基酸的不同水平产生多种反应。
