Jiang Y, Smale S T, Gralla J D
Department of Chemistry and Biochemistry, University of California, Los Angeles 90024.
J Biol Chem. 1993 Mar 25;268(9):6535-40.
The involvement of ATP during transcription initiation from three basic types of RNA polymerase II promoters was investigated. Hydrolysis of the beta-gamma bond of ATP was found to be required for transcription at TATA, initiator, and initiator + TATA promoters. For all three promoters, ATP is required to melt the transcription start site region during formation of a functional open transcription complex. The use of ATP to open the DNA strands occurs rapidly. The resulting open complex is transient, since the start site re-closes rapidly upon initiation. The requirements for efficient open complex formation were similar to those for transcription in that both upstream elements and a basal element, either TATA or initiator, were necessary. The results further suggest that TATA-dependent and initiator-dependent preinitiation complex assembly pathways converge, prior to a step in which the strands are rapidly opened in the presence of ATP, to form analogous open complexes.
研究了三磷酸腺苷（ATP）在三种基本类型的RNA聚合酶II启动子转录起始过程中的作用。发现在TATA、起始子以及起始子+TATA启动子的转录过程中，需要ATP的β-γ键水解。对于所有这三种启动子，在功能性开放转录复合物形成过程中，需要ATP来解开转录起始位点区域。利用ATP打开DNA链的过程迅速发生。所形成的开放复合物是短暂的，因为起始位点在起始后会迅速重新闭合。高效开放复合物形成的要求与转录的要求相似，即上游元件和一个基础元件（TATA或起始子）都是必需的。结果进一步表明，依赖TATA和依赖起始子的起始前复合物组装途径在一个步骤之前会合，在该步骤中，在ATP存在下链会迅速打开，以形成类似的开放复合物。
