The displacement of the two parts is 11 base pairs, or approximately one full turn of the DNA helix. Additional interactions between the protein and the first and last two bases occur within the DNA minor groove, where it is difficult for the protein to distinguish A from T, or G from C.
The data for this logo consists of 59 binding sites determined by DNA footprinting:
Robison, K., McGuire, A. M., Church, G. M. A comprehensive library of DNA-binding site matrices for 55 proteins applied to the complete Escherichia coli K12 genome. Journal of Molecular Biology (1998) 284, 241-254.