Scottish scientists have deciphered the three-dimensional structure of Wza, an integral outer-membrane protein that has been linked to virulence.
Many bacteria possess an external "capsule" of secreted polysaccharide molecules that help them to colonize surfaces, the researchers said, and Wza is responsible for moving such polysaccharides from the inside to the outside of the bacteria where they can function. The capsule is effectively the first point of contact between host and pathogen, making it a potential target for vaccines and other therapies.
The X-ray crystal structure the scientists deciphered reveals that most of Wza is located in the space between the inner plasma membrane and the outer cellular membrane or periplasm.
The protein, described by James Naismith and colleagues at St. Andrews University, contains a large central cavity through which the polysaccharides are transported.
The researchers say understanding the protein's structure should also contribute to a broader understanding of how other large polar molecules, such as DNA and proteins, are exported from cells.
The study appears online in the journal Nature.
Copyright 2006 by United Press International
Related stories:
SEX4, starch and phosphorylation
Some of the new molecular mechanisms and regulatory components in starch metabolism have been identified by Dr. Samuel Zeeman and his colleagues. Dr. Zeeman, of the Institute of Plant Sciences, ETH Zurich, in Switzerland, who is the 2007 recipient of the Charles Albert Shull Award, will be presenting this work at the opening Awards Symposium of the annual meeting of the American Society of Plant Biologists in Mérida, Mexico (June 27, 2:30 PM). Mutational and structural analyses by Dr. Zeeman and his colleagues have revealed that starch degradation in Arabidopsis leaves at night differs significantly from the versions traditionally described in textbooks. Specifically, mutations at the Starch Excess 4 (SEX4), Maltose Excess 1 (MEX1) and other loci produce plants unable to metabolize starch to a usable form.
New approach to fighting obesity and diabetes
World-first equipment, made exclusively for UQ scientists, will determine how to produce food which is better for us, but still tastes good.
Form Determines Function
A team of researchers at the Universities of Bielefeld and Hamburg (Germany) has now produced cyclopeptides that imitate the HNK-1 carbohydrate from human natural killer cells.
Searching For Aliens
Chris McKay, a planetary scientist with the NASA Ames Research Center, is involved in nearly every investigation of interest to astrobiologists. He is working on the return to the moon with both the Lunar Precursor and Robotic Program and the Constellation Project.
Daimler and power group RWE to test electric car network in Berlin
German car maker Daimler and energy group RWE unveiled on Friday a pilot project to promote electric vehicles in Berlin that was inspired by one in London.
Cassini Images Ring Arcs Among Saturn's Moons
(PhysOrg.com) -- NASA's Cassini spacecraft has detected a faint, partial ring orbiting with one small moon of Saturn, and has confirmed the presence of another partial ring orbiting with a second moon. This is further evidence that most of the planet's small, inner moons orbit within partial or complete rings.
Michigan integral to world's largest physics experiment
After 20 years of construction, a machine that could either verify or nullify the prevailing theory of particle physics is about to begin its mission. CERN's epic Large Hadron Collider (LHC) project currently involves 25 University of Michigan physicists and students. More than 100 U-M researchers have been involved in the project over the years. CERN is the European Organization for Nuclear Research, located in Geneva, Switzerland.
Atomic structure of the mammalian 'fatty acid factory' determined
Mammalian fatty acid synthase is one of the most complex molecular synthetic machines in human cells. It is also a promising target for the development of anti-cancer and anti-obesity drugs and the treatment of metabolic disorders. Now researchers at ETH Zurich have determined the atomic structure of a mammalian fatty acid synthase. Their results have just been published in
Science magazine.