Why are region called promoters essential to RNA transcription?

A promoter is a region of DNA where transcription of a gene is initiated. Promoters are a vital component of expression vectors because they control the binding of RNA polymerase to DNA. RNA polymerase transcribes DNA to mRNA which is ultimately translated into a functional protein.

Promoter. A promoter is a sequence of DNA needed to turn a gene on or off. The process of transcription is initiated at the promoter. Usually found near the beginning of a gene, the promoter has a binding site for the enzyme used to make a messenger RNA (mRNA) molecule.

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