Crystal structure of TtgV in complex with its DNA operator reveals a general model for cooperative DNA binding of tetrameric gene regulators - Lu, D; Fillet, S; Meng, C; Alguel, Y; Kloppsteck, P; Bergeron, J; Krell, T; Gallegos, M-T; Ramos, J; Zhang, X (GENES & DEVELOPMENT, 2010)