This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Microbial cell factories that produce pharmaceutical ingredients and other useful compounds include both the bacterium Escherichia coli and yeast, the organism used to leaven bread and ferment alcohol. The two organisms turn genes on by different rules, so a production design built for one has been hard to transfer to the other.
A KAIST research team has now built a gene control element that works in both and tested it using a green pigment whose production requires several genes working together. The work is expected to help researchers select the microbe best suited to producing a target compound. A research team led by Juyoung Lee, a professor at the Graduate School of Engineering Biology, has developed a "hybrid promoter," a gene control element that works in both E. coli and yeast, two very different types of microorganism.
The work was published in Nucleic Acids Research. For a microbe to make a target compound, the genes responsible for producing it must be turned on. A promoter is the stretch of DNA located in front of a gene that controls how strongly that gene works.
The challenge is that E. coli and yeast turn genes on in different ways, and a promoter that performs well in E. coli may not work at all in yeast. Making the same compound in a different microbe has therefore required choosing a promoter suited to that host and retuning the output of each gene from the beginning. The team's hybrid promoter combines, within a single sequence, DNA elements that E. coli and yeast each recognize.
It is, in effect, a shared control element designed so that each organism can find the signals it needs even though the two read genes differently. By varying the combination of these elements, the researchers built a series of promoters ranging in strength from weak to strong. The promoters worked in both hosts, and combinations that were strong in E. coli were generally strong in yeast as well.
That does not mean the two microbes make equal amounts of a compound; it means the relative ranking of promoter strengths from weak to strong is preserved across hosts. The team then tested whether the new control element could do more than turn on a single gene and could also be used for compound production. They chose a green pigment whose production requires three genes acting in sequence.
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