Promoter - A sequence of DNA upstream from the transcription start site, leader sequence and structural genes. The promoter is not transcribed. Consensus sequence - does not vary very much from one organism to another. Promoters have two consensus sequences. 35 bases upstream.
Transcription start site - downstream from the promoter.
Operator site - A site, on DNA, after the transcription start site where the repressor attaches which will modify transcription. It may be coding or non-coding. It is between leader and leader and start site for protein synthesis. Formyl is revoved. Trailer sequence - Downstream from the last structural gene.