Featured Research

from universities, journals, and other organizations

New Protein Structure Is A First Step Toward Preventing E. Coli Diseases

Date:
November 22, 2004
Source:
Brookhaven National Laboratory
Summary:
Scientists from the U.S. Department of Energy’s Brookhaven National Laboratory and Stony Brook University have determined the two-dimensional crystal structure of a membrane protein involved in the process by which the Escherichia coli (E. coli) bacteria infects a human. This protein structure is a first step to better understanding how an E. coli infection begins, which may lead to information on how to block it.

Brookhaven biologist Huilin Li.
Credit: Photo courtesy of Brookhaven National Laboratory

UPTON, NY - Scientists from the U.S. Department of Energy’s Brookhaven National Laboratory and Stony Brook University have determined the two-dimensional crystal structure of a membrane protein involved in the process by which the Escherichia coli (E. coli) bacteria infects a human. This protein structure is a first step to better understanding how an E. coli infection begins, which may lead to information on how to block it.

“E. coli is responsible for urinary tract infections, one of the most prevalent diseases in the U.S.,” said Brookhaven biologist Huilin Li, the lead researcher on the study, described in the November 2, 2004, online edition of the Journal of Molecular Biology. “Between 50 and 80 percent of U.S. women will experience a urinary tract infection at least once during their lifetimes.”

“In the first stage of the infection, E. coli binds tightly to human kidney cells, using an ‘adhesive protein’ secreted by the cells through a membrane protein ‘channel.’ Our structure of this protein channel helps show how secretion occurs, which may eventually lead us to determine how to stop E. coli from attaching to the human cell,” said Li.

The protein channel, known as “PapC,” is a member of the “chaperone/usher” family, channels that not only provide a pathway for certain substances to leave a cell but also participate in preparing the substance for secretion. In this case, PapC gathers the “parts” that make up the adhesive and then guides the assembled adhesive out of the cell.

Li and his colleagues found that PapC consists of two main structural elements, with each part containing one opening, or pore. Each pore is approximately two nanometers (billionths of a meter) in diameter, and the entire structure is 11 nanometers in length and seven nanometers wide.

While this structure might suggest that PapC uses both pores simultaneously, the researchers think that only one of the two pores may be in use at once. However, the twin pore configuration might be necessary to coordinate the assembly and secretion of the adhesive. This is consistent with other membrane proteins that perform similar functions.

“Our finding provides new insight into how the adhesive protein is assembled and secreted, but we need to know more about this process,” said Li. “A greater understanding of this will aid in the study and treatment of urinary tract infections and other related diseases.”

To determine the structure, the researchers grew a two-dimensional crystal of PapC – a sheet with a thickness of just one protein. To image individual proteins in the crystal, they used a technique called cryo-electron microscopy. In this method, the crystal is cooled to about minus 300 degrees Fahrenheit using liquid nitrogen and placed in an electron microscope. This device bombards the sample with high-energy electrons, which scatter off the atoms in the crystal. A lens inside the microscope focuses these electrons, forming a high-resolution image, which is recorded using film or a digital camera. The recorded images are analyzed by a computer, yielding the structure of the protein molecule.

This method produced a top-down image of the protein channel from an “untilted” sheet of crystals – that is, the electron beam hit the sheet head-on. To determine the channel’s three-dimensional structure, Li and his group plan to perform additional high-resolution imaging experiments using the same crystal sheet, but tilting it to large angles. This will allow the electrons to scatter off and produce an image of the protein channel’s other sides.

This research is a collaborative effort between researchers in Brookhaven Lab’s Biology Department, Tianbo Liu of Brookhaven’s Physics Department, and David Thanassi, a biologist in Stony Brook University’s Department of Molecular Genetics and Microbiology. The research was funded by a Brookhaven Laboratory Directed Research and Development grant, the National Institutes of Health, and the Office of Biological and Environmental Research within the U.S. Department of Energy’s Office of Science.

Related Link

* Huilin Li web page -- http://www.biology.bnl.gov/structure/li.html


Story Source:

The above story is based on materials provided by Brookhaven National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Brookhaven National Laboratory. "New Protein Structure Is A First Step Toward Preventing E. Coli Diseases." ScienceDaily. ScienceDaily, 22 November 2004. <www.sciencedaily.com/releases/2004/11/041116232602.htm>.
Brookhaven National Laboratory. (2004, November 22). New Protein Structure Is A First Step Toward Preventing E. Coli Diseases. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2004/11/041116232602.htm
Brookhaven National Laboratory. "New Protein Structure Is A First Step Toward Preventing E. Coli Diseases." ScienceDaily. www.sciencedaily.com/releases/2004/11/041116232602.htm (accessed October 22, 2014).

Share This



More Matter & Energy News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
China Airlines Swanky New Plane

China Airlines Swanky New Plane

Buzz60 (Oct. 21, 2014) China Airlines debuted their new Boeing 777, and it's more like a swanky hotel bar than an airplane. Enjoy high-tea, a coffee bar, and a full service bar with cocktails and spirits, and lie-flat in your reclining seats. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins