SEP 12, 2018 5:33 PM PDT

Tightening Control of Bacterial Gene Expression

WRITTEN BY: Carmen Leitch

Bacteria are easy to work with; their genes can be manipulated, and it’s usually easy to grow a lot of them. As such, they have a lot of potential as mini-factories that could produce many kinds of chemicals, from therapeutics to fuels. But one hurdle has been finding an affordable way to get the expression of those bacterial genes under control. To overcome that challenge, scientists from the Department of Energy's (DOE) Joint BioEnergy Institute, Lawrence Livermore National Laboratory (LLNL), Lawrence Berkeley National Lab and San Francisco State University have created a system to control gene expression; they called it "Jungle Express." This work has been reported in Nature Communications.

Colorized scanning electron micrograph of Escherichia coli / Image credit: NIAID

"We have created a system that can precisely control the timing and levels of expression of the genes involved in these processes, opening the way for efficient large-scale production at low costs," said LLNL biochemist Michael Thelen, senior author of the paper. "These enhancements to bacterial gene regulation have a potential translation to sustainable bioproduction."

Being able to turn genes on and off is fundamental to research and industry. While there have been ways to do this, they had issues. One difficulty was so-called leaky gene expression; there isn’t tight control of when genes are on or off, and improper regulation meant targets get made incorrectly or at the wrong levels. It was also an expensive problem.

"The key component of this expression system is a DNA binding protein that acts as a gene regulator," said Basel University graduate student Thomas Ruegg, who worked with Helen. "We used a computational approach to predict a small DNA sequence for optimal binding of the regulator protein."

Crystal violet is a common, inexpensive dye. Ruegg found that the dye quickly causes the gene regulator to release, turning gene expression on and generating biochemicals. "In a rational approach, we used the optimized DNA binding site to engineer a robust system in which crystal violet acts as the inducer to trigger efficient gene expression," Ruegg explained.

"Our findings have the potential to overcome the bottlenecks encountered in earlier systems and opens the way for tightly controlled and efficient gene expression that is not restricted to host organism, substrate or scale," Thelen added.

The name the team used, Jungle Express, comes from a rainforest bacterium, which is where the regulator protein from this work is found in nature. Ruegg noted that "it is a fascinating journey to explore the inexhaustible resource of genetic information found in microorganisms, and to decouple it from its native context for the development of novel, useful applications."

Learn more about how bacteria might be used to make valuable compounds from the video; EMBL discusses how to engineer a microbe that produces bioplastic.

 

Sources: Phys.org via LLNL, Nature Communications

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
DEC 11, 2019
Genetics & Genomics
DEC 11, 2019
The Cause of a New Autoimmune Disease is Discovered
Researchers have discovered a new autoinflammatory disease, which they have called CRIA (cleavage-resistant RIPK1-induced autoinflammatory) syndrome....
DEC 21, 2019
Genetics & Genomics
DEC 21, 2019
Genetics are a Poor Predictor of Most Diseases
In recent years, genetic testing models have gained tremendous popularity from their ability to predict one’s risk factor for developing, or contract...
DEC 29, 2019
Cell & Molecular Biology
DEC 29, 2019
A Molecular Switch for Modulating Gene Therapy Doses
  Genetic errors cause many different kinds of diseases, and gene therapy has aimed to relieve those symptoms by addressing the root cause....
JAN 10, 2020
Genetics & Genomics
JAN 10, 2020
Making Bad Fat Turn Good
Researchers want to turn unhealthy white fat, which stores calories, to healthier brown or beige fat that burns calories....
FEB 07, 2020
Genetics & Genomics
FEB 07, 2020
Mutations That Lead to Cancer May Occur Decades Before Diagnosis
As our cells age or divide, errors can accumulate in the genome they carry, which can lead to cancer, and a variety of environmental and genetic factors ca...
FEB 17, 2020
Microbiology
FEB 17, 2020
Giant Viruses Blur the Line Between Life and Non-Life
Bacteriophages, also known as phages, are more complex than many viruses that we know of, and often carry large genomes....
Loading Comments...