Molecular Anatomy of RNA Polymerase : Identification of Transcription Factor Contact Sites

RNA 聚合酶的分子解剖学：转录因子接触位点的鉴定

基本信息

批准号：
08458224
负责人：
ISHIHAMA Akira
金额：
$ 4.74万
依托单位：
National Institute of Genetics
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

The RNA polymerase holoezyme of Escherichia coli is composed of core enzyme with the subunit structure of alpha_2betabeta' and one of seven different molecular species of sigma subunits, each recognizing a different promoter sequence. The promoter selectivity of RNA polymerase is further modulated after interaction with one or two of more than 100 different species of trans-acting protein and nucleotide factors, generally designated as transcription factors, with the regulatory activities of transcriprion. The RNA polymerase activity is also modulated by cis-acting regulatory DNA signals generally located upstream of promoters. The contact sites on RNA polymerase subunits have been determined for more than 30 transcription regulatory protein or nucleotide factors. Based on the contact sites, we proposed to classify the transcription factors into four groups : clss-I(alpha contact), II(sigma contact), III(beta contact) and VI(beta' contact) factors. The contact sites estimated from mutant studies have been confirmed using a new tool of chemical reagent, Fe-BABE,with contact-dependent cleavage activity of DNA and proteins.Since the total number of RNA polymerase core enzyme is fixed at a low and constant level characteristic of the rate of cell growth, the concentrations of each from holoenzyme and ezch RNA polymerase-transcription factor complex are subject to fluctuation depending on growth-dependent variations in the concentrations of each sigma subunit and each transcription factor. Variation in the molecular arhitecture of transcription apparatus was analyzed during growth transition of E.coli from exponentially growing to stationary phase. Accordingly, the species and order of gene transcription among about 4,000 genes on the E.coli chromosome change depending on the cell growth conditions.

大肠杆菌的RNA聚合酶全酶由核心酶与alpha_2betabeta'的亚基结构组成，是七种不同的Sigma亚基分子种类之一，每个分子均认识到不同的启动子序列。与经transcriprion的调节活性相互作用，与100多种不同种类的反式蛋白质和核苷酸因子相互作用后，进一步调节了RNA聚合酶的启动子选择性。 RNA聚合酶活性还通过通常位于启动子上游的顺式调节DNA信号来调节。已经确定了30多个转录调节蛋白或核苷酸因子的RNA聚合酶亚基上的接触位点。基于接触站点，我们提议将转录因子分为四组：CLSS-I（Alpha接触），II（Sigma接触），III（beta触点）和VI（beta's tocture）因子。 The contact sites estimated from mutant studies have been confirmed using a new tool of chemical reagent, Fe-BABE,with contact-dependent cleavage activity of DNA and proteins.Since the total number of RNA polymerase core enzyme is fixed at a low and constant level characteristic of the rate of cell growth, the concentrations of each from holoenzyme and ezch RNA polymerase-transcription factor complex are subject to fluctuation depending on每个Sigma亚基和每个转录因子浓度的生长依赖性变化。在大肠杆菌从指数生长到固定相的生长过渡过程中，分析了转录设备的分子峰值的变化。因此，根据细胞生长条件，大约4,000个基因之间的基因转录的物种和顺序在大肠杆菌染色体上的变化。