Molecular structure explains how ‘arsenic life’ bacteria rely on phosphate instead
Hardy bacteria that live in an arsenic bath survive in part by keeping poison from entering their cells, scientists have found. Just one tiny tweak in a hydrogen bond is enough to let the microbes pick out the phosphate they need to build their DNA — while keeping the arsenic out.
The work helps explain how famous bacteria in the arsenic-rich waters of Mono Lake, Calif., manage to live there without incorporating arsenic into their DNA, as a controversial 2010 paper had claimed (SN: 2/25/12, p. 10).
“It goes to show that life will find a way,” says Matthew Pasek, a geochemist at the University of South Florida who was not involved in the new study.
The discovery may also open new ways to deliver substances into a cell that are wanted, like drugs, while keeping unwanted stuff out. “The best way of avoiding poison is not to take it, and this is like the first defense mechanism,”