Featured Research

from universities, journals, and other organizations

First 'Molecular Snapshot' Of A Virulence Factor On Bacterial Surface

Date:
June 6, 2008
Source:
Stony Brook University Medical Center
Summary:
Scientists have captured a view of proteins during translocation across the bacterial outer membrane, for the first time. This "molecular snapshot" may enlighten scientists to the process of protein secretion across membranes, a problem faced by all cells, and provide a foundation to understanding certain bacterial virulence factors that allow bacteria to cause disease.

A model built that is based on the "molecular snapshot" of pilus assembly at the bacterial outer membrane by the twin pores usher complex.
Credit: Image courtesy of Stony Brook University Medical Center

David G. Thanassi, Ph.D., and co-investigators from Stony Brook University, Brookhaven National Laboratory, Washington University, and University College in London, are the first to capture a view of proteins during translocation across the bacterial outer membrane. This “molecular snapshot” may enlighten scientists to the process of protein secretion across membranes, a problem faced by all cells, and provide a foundation to understanding certain bacterial virulence factors that allow bacteria to cause disease.

Related Articles


The investigators used X-ray crystallography to determine the structure of a protein – called the usher – that is part of the chaperone/usher pathway and serves as a molecular scaffold for the assembly of adhesive pili by pathogenic bacteria such as E. coli. Pili are hair-like fibers that form a class of virulence factors that allow bacteria to attach to host cells and cause disease.

In addition to the crystal structure analysis of the usher, the researchers used electron microscopy imaging to capture a “molecular snapshot” of the pilus fiber during the act of secretion through the usher to the cell surface. These structures show the pilus assembly machinery in action during the bacterial outer membrane translocation process. The usher contains two channels or “twin pores.”

Dr. Thanassi said the team discovered that only one of these pores is used for secretion while the other remains closed. This discovery – and others the team anticipates to find – provides insight into the secretion of virulence factors across the outer membrane of Gram-negative bacteria.

“This ‘molecular snapshot’ is a new way to look at and analyze virulence factors assembled by bacteria,” says Dr. Thanassi of the Stony Brook University Center for Infectious Diseases, and Associate Professor, Department of Molecular Genetics and Microbiology. “The snapshot provides us with a window to viewing protein secretion across membranes and understanding how disease-causing bacteria assemble virulence factors on their surface. This method may help us to target virulence factors that allow bacteria to cause disease, which would ultimately lead to a new approach to antibiotics.”

In an accompanying commentary to the article in the journal, scientists from the Swedish Institute for Infectious Disease Control and the Karolinska Institute in Sweden stated that the “new structures provide the first detailed view of a translocase in action [and] at astounding resolution.” The scientists further commented, “the present work combined with several other studies positions the chaperone usher pathway as the most mechanistically understood translocation process at a structural level.”

Dr. Thanassi’s co-authors on the study include: Huilin Li, Ph.D., Department of Biochemistry & Cell Biology, Stony Brook University (SBU), and Biology Department, Brookhaven National Laboratory (BNL); Han Remaut, Ph.D., Institute of Structural Molecular Biology, University College in London; Chanyan Tang, Ph.D., Biology Department, BNL; Nadine S. Henderson, Center for Infectious Diseases, SBU; Jerome S. Pinker, Department of Molecular Microbiology, Washington University; Tao Wang, Ph.D., Biology Department, BNL; Scott J. Hultgren, Ph.D., Department of Molecular Microbiology, Washington University; and Gabriel Waksman, Ph.D., Institute of Structural Molecular Biology, University College in London.


Story Source:

The above story is based on materials provided by Stony Brook University Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. REMAUT et al. Fiber Formation across the Bacterial Outer Membrane by the Chaperone/Usher Pathway. Cell, 2008; 133 (4): 640 DOI: 10.1016/j.cell.2008.03.033

Cite This Page:

Stony Brook University Medical Center. "First 'Molecular Snapshot' Of A Virulence Factor On Bacterial Surface." ScienceDaily. ScienceDaily, 6 June 2008. <www.sciencedaily.com/releases/2008/05/080531091842.htm>.
Stony Brook University Medical Center. (2008, June 6). First 'Molecular Snapshot' Of A Virulence Factor On Bacterial Surface. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2008/05/080531091842.htm
Stony Brook University Medical Center. "First 'Molecular Snapshot' Of A Virulence Factor On Bacterial Surface." ScienceDaily. www.sciencedaily.com/releases/2008/05/080531091842.htm (accessed October 26, 2014).

Share This



More Plants & Animals News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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