Transcriptional Promoters
A
promoter is a short
DNA sequence that signals the RNAPol
where to begin transcription. Comparison of many E. coli
DNA gene sequences shows two common promoter motifs [yellow
boxes] with similar
sequences, which are
located approximately -10 [the TATA Box] & -35
[the CAT Box] bases 5' ('upstream') from the start point of RNA
transcription [blue box]. Similar promoter regions occur in other prokaryotic
and eukaryotic genes.
It is important to remember that the promoter is a DNA signal for the downstream start point of transcription at position +1. The start point of translation is recognizable in the DNA still further downstream, but is actually on the transcribed RNA molecule, at the AUG start codon of the gene. The start codon does not appear in the diagram.
It is important to remember that the promoter is a DNA signal for the downstream start point of transcription at position +1. The start point of translation is recognizable in the DNA still further downstream, but is actually on the transcribed RNA molecule, at the AUG start codon of the gene. The start codon does not appear in the diagram.
Figure © 2004 by Griffiths et al. ; text © 2024 by Steven M. Carr