Organization of a eukaryotic protein-coding gene region
convention, the upstream
to the 5' 3'
direction of the DNA sense strand; it is
ordinarily drawn left to right for convenience.
The transcriptional unit comprises
the expressed exons and intervening
as well as 5' non-coding
sequences required for
RNA polymerase binding (Shine-Delgarno sequence)
and trailing 3' non-coding sequences. Outside the
transcriptional area, the 5'
flanking region ("upstream")
region includes the 'CAT box' and 'TATA box' promoters required
for RNA polymerase
recognition prior to transcription.
Enhancers that regulate occurrence, timing,
and amount of transcription occur in both the upstream region
the 3' flanking region
region; multiple enhancers may occur many hundreds of
Figure © 1997
Klug & Cummings; text © 2014 by Steven M. Carr