Stress control for a well-structured life.

Aerobic life brings with it a need to respond to external redox stress in ways that preserve key processes. Suppressor of copper sensitivity (Scs) proteins contribute to this response in some bacteria, but have poorly defined molecular functions. Furlong et al. now demonstrate that two Scs proteins from Proteus mirabilis provide a redox relay functionally equivalent to, but structurally distinct from, the Dsb proteins that orchestrate disulfide bonding in Escherichia coli, emphasizing the wide prevalence of this mechanism in bacteria.