Structural basis for activation of a diguanylate cyclase required for bacterial predation in Bdellovibrio

The initiation of prey invasion by the predatory bacterium Bdellovibrio bacteriovorus is governed by the activity of the diguanlylate cyclase DgcB. Here the authors show that the stimulus regulating DgcB activity is a phosphopeptide derived from DgcB itself and present the crystal structures of full-length DgcB and of its empty and peptide-bound sensor domain.