MashGet

Promoter from WikiPedia:

In genetics, a promoter is a region of DNA that facilitates the transcription of a particular gene. Promoters are typically located near the genes they regulate, on the same strand and upstream (towards the 5' region of the sense strand).

In order for transcription to take place, the enzyme that synthesizes RNA, known as RNA polymerase, must attach to the DNA near a gene. Promoters contain specific DNA sequences and response elements which provide a binding site for RNA polymerase and for proteins called transcription factors that recruit RNA polymerase.

• In bacteria, the promoter is recognized by RNA polymerase and an associated sigma factor, which in turn are often brought to the promoter DNA by an activator protein binding to its own DNA binding site nearby.

• In eukaryotes, the process is more complicated, and at least seven different factors are necessary for the binding of an RNA polymerase II to the promoter.

Read more on WikiPedia