Transcriptional Promoters

A promoter is a short DNA sequence that signals the RNAPol to begin transcription. Comparison of many E. coli DNA gene sequences shows two common promoter motifs, located approximately -10 & -35 bases from the startpoint of RNA transcription, with similar sequences. It is important to remember that the startpoint of transcription is itself physically separated from the start codon of the gene, which signals the startpoint of translation, and which does not appear in the diagram. Similar promoter regions occur in other prokaryotic and eukaryotic genes.


Figure © 2000 by Griffiths et al. ; text © 2004 by Steven M. Carr