Activity of each construct was determined . the basal promoter was located at about 60bp up stream of the transcription initiation site . it contains a tata box at - 33bp which is required for the transcription initiation 基因的基本启动子元件位于转录起始位点上游约60bp ,其中含有一个位于- 33bp处的tatabox ,它对于转录起始起着重要作用。