The diagram below shows the upstream region and the core promoter (region E with
ID: 44390 • Letter: T
Question
The diagram below shows the upstream region and the core promoter (region E with TATA box). The upstream region has been divided into four regions, labeled A?D. To identify enhancer and suppressor regions in the upstream region, your fused either the entire DNA sequence (including regions A to E) or the DNA sequence lacking one of these regions to lacZ. These recombinant molecules are introduced into human cell cultures. The activity of galactosidase in cells containing the full length i.e, with all five regions or lacking one of the five regions is shown in the table below.
Explain what these results mean. Does it have any enhancers or suppressors? If they do, which parts of the upstream region contain these?
Explanation / Answer
All regions in the upstream sequence gives a 100% activity. The deletion of A region does not affect the activity, so it is neither a suppressor or a enhancer. The deletion of B region drastically increased the activity by 330%, which implies the B region being the suppressor. The deletion of C region does not affect the activity. The deletion of D region drastically reduced the activity, which implies that this region is the enhancer in the gene.