Team:Penn State/Bidirectional Promoters

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Bidirectional Promoters Overview

Bidirectional Promoters

Scientists are frequently confounded by wayward promoters; that is, promoters which do not produce the expected proteins. Some bidirectional promoters are known to exist, but which way they promote and the degree of expression has not been quantified. This project will test the directionality of several BioBrick promoters to answer these questions.

Bidirectional Promoters

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Overview | Design | Results

Background

Before we can make a protein, we need an mRNA to carry the information about the order of the amino acids. But before we can make mRNA we need to know where the genes are in the DNA of a cell. Before RNA polymerase can make a copy it needs to bind to the DNA. This is assisted by a variety of factors, other proteins, that look for a specific sequence in the DNA. This sequence is called a promoter because it promotes the transcription of the DNA into RNA by the RNA polymerase. These sequences are generally upstream, or ahead, of a gene's coding sequence.

The Problem

Not all promoters cause RNA polymerase to transcribe downstream in the expected "forward direction". Some promoters can cause RNA polymerase to go in the opposite direction from what is expected, or go in both directions. This is what we are trying to find out; do different promoters go in different directions, and what is the directional preference of different promoters.