A protein secreted by the chlamydia bug has a very unusual structure, according to scientists in the School of Medicine at The University of Texas Health Science Center San Antonio. The discovery of the protein's shape could lead to novel strategies for diagnosing and treating chlamydia, a sexually transmitted disease that infects an estimated 2.8 million people in the U.S. each year.
The protein, Pgp3, is secreted by Chlamydia trachomatis, the bacterium that causes chlamydia. Pgp3's shape is very distinguishable — sort of like an Eiffel Tower of proteins. "From a structural standpoint, the protein is very odd indeed," said X-ray crystallographer P. John Hart, Ph.D., the Ewing Halsell President's Council Distinguished Chair in the Department of Biochemistry at the San Antonio medical school. "This long and slender molecule contains a fusion of structural motifs that resemble those typically found in viral and not bacterial proteins." Dr. Hart is co-lead author of the research, which is described in the Journal of Biological Chemistry (JBC).
The Pgp3 protein is a chlamydial virulence factor that is hypothesized to enhance the bug's ability to initially infect its human host and then evade host defenses. "Although my lab has worked on this protein for many years and gained a great deal of knowledge on it, we still don't know what roles it may play in chlamydial pathogenesis (disease development)," said co-lead author Guangming Zhong, M.D., Ph.D., professor of microbiology at the Health Science Center. "With the structural information uncovered in this paper, we can now test many hypotheses."
This is the second chlamydial virulence factor that Dr. Zhong's laboratory has identified; the first was a protein called CPAF. Structural studies have played an important role in understanding CPAF's functions in chlamydial infections, Dr. Zhong said.
According to the U.S. Centers for Disease Control and Prevention (CDC), more than 1.4 million new cases of chlamydia were reported in 2011 across the 50 states and the District of Columbia. But the CDC says as many cases go unreported because most people with chlamydia have no symptoms and do not seek testing. If left untreated, chlamydia can permanently damage a woman's reproductive system. This can lead to ectopic pregnancy, pelvic inflammatory disease and infertility.
The disease burden of chlamydia worldwide is magnitudes greater, with new cases numbering in the dozens of millions per year. The World Health Organization estimates that 499 million new cases occur annually of four curable sexually transmitted diseases — chlamydia, syphilis, gonorrhea and trichomoniasis. This estimate is for cases in adults aged 15-49.Chlamydia infection induces inflammatory pathology in humans, and Pgp3 may contribute to the pathology by activating inflammation via one of its structural features uncovered in the crystal structure, said Dr. Zhong, who has worked with Dr. Hart on the Pgp3 project for nearly four years.
Structure of the Chlamydia trachomatis Immunodominant Antigen Pgp3Ahmad Galaleldeen 1,4,#, Alexander B. Taylor 1,3,#, Ding Chen 2, Jonathan P. Schuermann 5, Stephen P. Holloway 1, Shuping Hou 2, Siqi Gong 2, Guangming Zhong 2 and P. John Hart 1,3,6
#These authors contributed equally to this work.
On the Web, Facebook and Twitter
For current news from the UT Health Science Center San Antonio, please visit our news release website, like us on Facebook or follow us on Twitter.
About the UT Health Science Center San Antonio
The University of Texas Health Science Center at San Antonio, one of the country's leading health sciences universities, ranks in the top 3 percent of all institutions worldwide receiving National Institutes of Health funding. The university's schools of medicine, nursing, dentistry, health professions and graduate biomedical sciences have produced approximately 28,000 graduates. The $736 million operating budget supports eight campuses in San Antonio, Laredo, Harlingen and Edinburg. For more information on the many ways "We make lives better®," visit http://www.uthscsa.edu.
Will Sansom | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences