promoter

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promoter

genetics

Also known as: enhancer, modulator

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July 13, 2026

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A promoter is a region of DNA that initiates the transcription of a gene. It is located near the start of a gene and serves as the binding site for RNA polymerase, the enzyme responsible for synthesizing RNA from a DNA template. Promoters are crucial for regulating gene expression, determining when and where a gene is turned on or off.12

In bacteria, promoters are often part of an operon, a cluster of genes with related functions. The promoter, along with other regulatory elements like operators, controls the transcription of these genes. In eukaryotes, promoters are more complex and often require transcription factors to activate or repress gene expression. These regulatory proteins bind to specific DNA sequences within or near the promoter, influencing the rate at which RNA polymerase initiates transcription.321

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heredity
Transcription
…and a region called the promoter, to which the RNA polymerase binds. These sequences must be a specific distance from the transcriptional start site for successful operation. Various short base sequences in this regulatory region physically bind specific transcription factors by virtue of a lock-and-key fit between the DNA and…
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…and a region called the promoter, to which the RNA polymerase binds. These sequences must be a specific distance from the transcriptional start site for successful operation. Various short base sequences in this regulatory region physically bind specific transcription factors by virtue of a lock-and-key fit between the DNA and…
Read More

operon
…under the control of one promoter (a short segment of DNA to which the RNA polymerase binds to initiate transcription). A single unit of messenger RNA (mRNA) is transcribed from the operon and is subsequently translated into separate proteins.
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…under the control of one promoter (a short segment of DNA to which the RNA polymerase binds to initiate transcription). A single unit of messenger RNA (mRNA) is transcribed from the operon and is subsequently translated into separate proteins.
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nucleic acid
Transcription
…sequence on DNA called a promoter that signifies the start of the gene. The two strands of DNA become separated at this point, and RNA polymerase begins copying from a specific point on one strand of the DNA using a ribonucleoside 5′-triphosphate to begin the growing chain. Additional ribonucleoside triphosphates…
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…sequence on DNA called a promoter that signifies the start of the gene. The two strands of DNA become separated at this point, and RNA polymerase begins copying from a specific point on one strand of the DNA using a ribonucleoside 5′-triphosphate to begin the growing chain. Additional ribonucleoside triphosphates…
Read More

transposon
Transposons and disease
For example, insertions near promoter regions, which are short segments of DNA that are used to initiate gene transcription (the synthesis of RNA from DNA), can lead to overactivity of genes. In some cases this can give rise to cancer. In other cases the site where a class II…
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For example, insertions near promoter regions, which are short segments of DNA that are used to initiate gene transcription (the synthesis of RNA from DNA), can lead to overactivity of genes. In some cases this can give rise to cancer. In other cases the site where a class II…
Read More