Navigation Links
Basic work on E. coli identifies two new keys to regulation of bacterial gene expression

The cellular process of transcription, in which the enzyme RNA polymerase constructs chains of RNA from information contained in DNA, depends upon previously underappreciated sections of both the DNA promoter region and RNA polymerase, according to work done with the bacterium E. coli and published today (June 16) in the journal Cell by a team of bacteriologists from the University of Wisconsin-Madison.

This fundamental research about a key step in RNA synthesis has important implications for the study of gene expression in other organisms, and adds to the wealth of knowledge about E. coli contributed by scientists from the UW-Madison.

"The kinds of processes that we study in E. coli happen in a wide variety of bacteria of medical, environmental and agricultural importance," notes Rick Gourse, a professor of bacteriology who published the Cell paper along with a team from his lab. "This knowledge can ultimately be put to use in systems that aren't so amenable to investigation, such as bacteria that cause cholera, produce anthrax toxin or lead to ulcers and stomach cancer."

Scientists use model organisms because they are relatively easy to work with and because there is a vast amount of previous knowledge about them. They can then test whether their findings in model organisms hold true in other species, says Gourse, who studies a strain of E. coli that while harmless, is closely related to disease-causing varieties like E. coli 0157:H7.

"Basic research in E. coli is very important," says Gourse. "Much of what we know about gene expression both in bacteria and in higher life forms comes from work performed originally on this model organism." The strain that Gourse works with is one of the most well-studied species in biology and has important ties to the UW-Madison.

In his most recent study, Gourse investigated the interaction between RNA polymerase and promoters from the E. coli chromosome. RNA polymerase reads the informat ion in DNA and transcribes it into chains of RNA, which are later translated into proteins. Promoter regions are specific sequences within the DNA chain that tell RNA polymerase when and where to begin transcription, and how much product to make from specific genes.

Gourse's group found that there is a specific region within DNA promoters that makes contact with a highly conserved but previously underappreciated segment of the sigma subunit of RNA polymerase. While the contact with sigma is very strong at promoters for most genes, it is particularly weak at promoters that make ribosomal RNA, which means that other factors like nutritional and environmental signals ultimately regulate the expression of those genes.

"In this case, regulation is achieved not because the promoter makes a special contact, but because it can't establish contact at all," says Gourse. "This is an example of how sometimes less is more, and a probably very ancient example of one of the methods that arose through evolution to regulate gene expression."

Ribosomal RNA makes up the bulk of ribosomes, the molecular machines that make proteins and are present in huge numbers in all cells. Since so much of the cell's energy is used to make ribosomes, control of ribosomal RNA transcription is particularly crucial to a cell's well-being.

"This work is basic to the growth of all bacteria," says Gourse. "By understanding transcription and control of ribosome synthesis in E. coli, we can understand more about these processes in bacterial species that we need to control, like those that cause disease or make toxins. E. coli is also the workhorse of the biotechnology industry. Understanding E. coli gene expression in detail allows us to harness these cells for producing products of biotechnological importance, like pharmaceuticals."

Gourse's work was supported by the National Institutes of Health, the United States Department of Agriculture, and by Pfizer Biotechno logy. His team included graduate student Shanil Haugen; undergraduate Christopher Ward; and senior scientists Wilma Ross and Tamas Gaal.


'"/>

Source:University of Wisconsin-Madison


Related biology news :

1. Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST)
2. Basic research leads to a novel cancer therapy
3. Study identifies predictors of HIV drug resistance in patients beginning triple therapy
4. New lab technique identifies high levels of pathogens in therapy pool
5. Study identifies gene in mice that may control risk-taking behavior in humans
6. Researcher at UGA College of Veterinary Medicine identifies new way of combating viral diseases
7. U. of Colorado researcher identifies tracks of swimming dinosaur in Wyoming
8. Model identifies genes that induce normal skin cells to become abnormal
9. New study identifies key gene in development of connections between brain and spinal cord
10. New HIV study identifies high-risk subgroups of adolescents
11. Research identifies protein in mice that regulates bone formation
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:1/22/2016)... http://www.researchandmarkets.com/research/p74whf/global_biometrics ) ... "Global Biometrics Market in Retail Sector 2016-2020" ... --> http://www.researchandmarkets.com/research/p74whf/global_biometrics ) has announced the ... in Retail Sector 2016-2020" report to ... and Markets ( http://www.researchandmarkets.com/research/p74whf/global_biometrics ) has announced ...
(Date:1/18/2016)... , Jan. 18, 2016  Extenua Inc., ... that simplifies the use and access of ubiquitous ... go-to-market partnership with American Cyber.  ... extensive experience leading transformational C4ISR and Cyber initiatives ... integrating the latest proven technology solutions," said ...
(Date:1/11/2016)... Jan. 11, 2016  higi, the leading retail ... retail locations, web and mobile, today announced it ... from existing investors. --> ... to further innovate higi,s health platform – its ... portal – including expanding services and programs to ...
Breaking Biology News(10 mins):
(Date:2/4/2016)... MENLO PARK, Calif. , Feb. 4, 2016 /PRNewswire/ ... "Company"), a biopharmaceutical company focused on the development and commercialization ... at the 18 th Annual BIO CEO & ... a.m. EST in New York, NY . ... will provide an update on the ongoing clinical trial of ...
(Date:2/4/2016)... Feb. 4, 2016 Sinovac Biotech Ltd. ("Sinovac" ... provider of biopharmaceutical products in China ... board of directors received on February 4, 2016 a ... a consortium comprised of PKU V-Ming ( Shanghai ... Ltd., CICC Qianhai Development ( Shenzhen ) ...
(Date:2/3/2016)... , Feb. 3, 2016   ViaCyte, ... with the first pluripotent stem cell-derived islet replacement ... in clinical-stage development, today announced that ViaCyte and ... Companies of Johnson & Johnson, have agreed to ... into ViaCyte.  The agreement provides ViaCyte with an ...
(Date:2/3/2016)... and HOLLISTON, Mass., Feb. 3, 2016 Harvard ... a biotechnology company developing bioengineered organ implants for ... today announced that CEO Jim McGorry , ... Investor Conference on Tuesday, February 9, 2016 ... York City . HART,s presentation will be ...
Breaking Biology Technology: