RNA Polymerase II Promoters

We will focus most of our attention on promoters recognized by RNA polymerase II, which transcribes the genes that encode proteins. A promoter for a gene transcribed by RNA polymerase II typically consists of two primary parts: the core promoter and the regulatory promoter.

Core promoter The core promoter is located immediately upstream of the gene (I Figure 13.16) and typically includes one or more consensus sequences. The most common of these consensus sequences is the TATA box, which has the consensus sequence TATAAA and is located from —25 to —30 bp upstream of the start site. Mutations in the sequence of the TATA box affect the rate of transcription, and changing its position alters the location of the transcription start site.

Another common consensus sequence in the core promoter is the TFIIB recognition element (BRE), which has the consensus sequence G/C G/C G/C C G C C and is located from —32 to —38 bp upstream of the start site. (TFIIB is the abbreviation for a transcription factor that binds to this element; see next subsection). Instead of a TATA box, some core promoters have an initiator element (Inr) that directly overlaps the start site and has the consensus Y Y A N T/A Y Y. Another consensus sequence called the downstream core promoter element (DPE) is found

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