Promoter

In molecular biology, a site on DNA to which the enzyme RNA polymerase can bind and initiate the transcription of DNA into RNA.

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1. In chemistry, a substance that increases the activity of a catalyst. 2. In molecular biology, a DNA sequence at which RNA polymerase binds and initiates transcription.

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pro·mot·er -'mōt-ər n

1) a substance that in very small amounts is able to increase the activity of a catalyst

2) a binding site in a DNA chain at which RNA polymerase binds to initiate transcription of messenger RNA by one or more nearby structural genes

3) a chemical believed to promote carcinogenicity or mutagenicity

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(in oncogenesis)

n.

a substance that, in conjunction with an initiator, leads to the production of a cancer.

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pro·mo·ter (prə-moґtər) 1. a segment of DNA usually occurring upstream from a gene coding region and acting as a controlling element in the expression of that gene; it serves as a recognition signal for an RNA polymerase and marks the site of initiation of transcription. 2. a substance in a catalyst that increases the rate of activity of the catalyst. Cf. protector. 3. a type of epigenetic carcinogen that promotes neoplastic growth only after initiation by another substance; called also cocarcinogen.