The X-ray Crystal Structures of Two Constitutively Active Mutants of the Escherichia coli PhoB Receiver Domain Give Insights into Activation - Arribas-Bosacoma, R.; Kim, S.-K.; Ferrer-Orta, C.; Blanco, A.G.; Pereira, P.J.B.; Gomis-Rüth, F.X.; Wanner, B.L.; Coll, M.; Solà, M. (Journal of Molecular Biology, 2007)