Researchers uncover protein's job protecting pneumonia-causing pathogen from copper poisoning

January 29, 2013
A ribbon diagram depicts the three-dimensional structure of the copper-binding protein CupA found in the respiratory pathogen Streptococcus pneumoniae.

(—A team of chemists and biologists led by Indiana University chemistry professor David Giedroc has described a previously unknown function of a protein they now know is responsible for protecting a major bacterial pathogen from toxic levels of copper. The results were published Jan. 27 in Nature Chemical Biology.

Bacterial pathogens like —responsible for infections that include pneumonia, meningitis and sepsis—have evolved various strategies to limit copper levels in their cells to prevent toxicity.

"Copper is highly reactive metal and is carefully handled by all cells that require it. There is emerging evidence to suggest that human cells use copper toxicity as a weapon to kill microbial pathogens," Giedroc said. "The novel copper trafficking system that we describe in this paper represents a new functional twist on an evolutionary ancient family of proteins that opens up a potential new antibacterial strategy."

Giedroc and co-workers describe the structure and function of the protein CupA as a chaperone that buffers copper to very low concentrations—in turn protecting S. pneumoniae from damage.

"We're proposing that the primary role of CupA in S. pneumoniae is to bind near the plasma membrane as soon as they enter the cell and, after diffusion of copper-bound CupA in the membrane, to deliver copper directly to the exporter CopA, which extrudes copper out of the cell," Giedroc said.

Copper chaperones are known to exist in all cells from bacteria to humans. In this report, the authors describe a completely novel way in which a copper chaperone and a domain of a copper recipient , CopA, bind copper. Using —a technique to obtain mechanistic and structural information about molecules—they were able to determine the pathway by which copper is transferred from CupA to CopA.

"This work represents an excellent example of collaborative science that works so well on the Bloomington campus, teaming up structural biologists, a microbiologist and an inorganic chemist," Giedroc said. "This allowed us to grasp the biological significance of what is essentially novel coordination chemistry that bacteria use to protect themselves from copper-mediated killing."

Explore further: Dietary copper may ease heart disease

Related Stories

Dietary copper may ease heart disease

March 5, 2007

Including more copper in your everyday diet could be good for your heart, according to scientists at the University of Louisville Medical Center and the USDA Human Nutrition Research Center. Their studies show that giving ...

Breakthrough: With a chaperone, copper breaks through

October 18, 2010

( -- Information on proteins is critical for understanding how cells function in health and disease. But while regular proteins are easy to extract and study, it is far more difficult to gather information about ...

Recommended for you

New polymer creates safer fuels

October 1, 2015

Before embarking on a transcontinental journey, jet airplanes fill up with tens of thousands of gallons of fuel. In the event of a crash, such large quantities of fuel increase the severity of an explosion upon impact. Researchers ...

Researchers print inside gels to create unique shapes

September 30, 2015

(—A team of researchers at the University of Florida has taken the technique of printing objects inside of a gel a step further by using a highly shear-rate sensitive gel. In their paper published in the journal ...

How a molecular motor untangles protein

October 1, 2015

A marvelous molecular motor that untangles protein in bacteria may sound interesting, yet perhaps not so important. Until you consider the hallmarks of several neurodegenerative diseases—Huntington's disease has tangled ...

Anti-aging treatment for smart windows

October 1, 2015

Electrochromic windows, so-called 'smart windows', share a well-known problem with rechargeable batteries – their limited lifespan. Researchers at Uppsala University have now worked out an entirely new way to rejuvenate ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jan 29, 2013
Fascinating, not only is Brass Oligodynamic but Copper is a real threat to most bacteria, yet Copper is deficient in the majority of Western Diets and a component of Ferroxidase which is an enzyme to metabolise Iron... Here are a few related links related to Copper:-




Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.