The crystal structures of pumps that remove heavy metal toxins from bacteria, making them resistant to antibiotics, Iowa State University and the Ames Laboratory researchers have discovered.
It could help drug researchers develop treatments to combat that resistance, reports Nature.
Edward Yu and his colleagues purified and crystallized the membrane proteins that make up an efflux pump of E. coli bacteria. Then they used X-ray crystallography to compare the various structures, identify the differences and understand the mechanism that removes heavy-metal toxins from cells.
What those pumps do, Yu wrote, is "recognize and actively export these substances out of bacterial cells, thereby allowing the bugs to survive in extremely toxic conditions."
"This work reports the first detailed structure of a unique heavy metal transporter that enables bacteria to survive the toxic effects of silver and copper," said Jean Chin at the National Institutes of Health.
"By detailing the exact steps that a metal ion is likely to take through the transporter, this study suggests how we might block the pathway and render pathogenic bacteria sensitive to heavy metal toxins."
The findings are published in the Sept. 23 issue of the journal Nature.