Abstract
Iron is the most common transition metal cofactor across biological systems. As the earth transitioned from an anaerobic to aerobic environment, cellular mechanisms evolved to protect against iron-mediated oxidative damage, but the molecular details of these protective strategies remain unclear. In this report, the Lindahl group has combined spectroscopic, biochemical, and genetic approaches to inventory iron in Escherichia coli as a function of bacterial oxygen metabolism. Their results suggest that ferrous iron functions as an oxygen sink that is modulated by a "respiratory shield" of electron flux in the bacterial plasma membrane.