Figure 5

Enhanced superhelical motion by the non-RVD mutations to TALEN.

(a) The superhelical amplitude motion of VT-TALE is greater in magnitude compared with that of CT-TALE. The model TALE structures in different conformations occurred in the molecular dynamics simulation are located on the left to the schematic drawings. The canonical TAL-repeats, N-terminal atypical repeats and C-terminal half repeats are indicated as yellow, grey and white boxes, respectively. (b) The number of TAL-repeats in VT-TALE (lower) that engage in DNA binding is greater than that observed for CT-TALE (upper). The DNA-bound TAL-repeats are represented by orange boxes, and the free TAL-repeats are drawn as yellow boxes. The DNA bases specifically recognised by the TAL-repeats are presented as red bars. The modelled TALE structures in the complex with DNA are located on the left of the schematic drawings for the complexes having a different number of TAL-repeats engaged in the DNA binding. (c) The spatial restriction of the FokI domains by the extended TAL-repeat interaction to DNA in VT-TALE (lower) could facilitate FokI dimerisation more readily than that observed for CT-TALE (upper). FokI monomers are depicted as cyan semicircles. The arrows schematically represent the magnitudes of the structural dynamics of the TAL-repeats not bound to DNA and the FokI domain associated with the C-terminal end of the TAL-repeat array.