Question: what is an important difference between enhancers and promoter-proximal activators?
Answer: Promoter-proximal elements, which are relatively short (≈15–30 base pairs), are located within the first ≈200 base pairs upstream of the cap site. Enhancers, in contrast, usually are 100 – 200 base pairs long and may be located up to 50 kilobases upstream or downstream from the cap site or within an intron.