Figure 1

TALE sequence and structure.

(a) Comparison between the amino acid sequences of the first 4 TAL-repeats of TALE with/without the periodically mutated repeats. The sequences of TAL-repeats without (CT-TALE, upper) and with the periodical mutations (VT-TALE, lower) are presented. RVDs are shaded in cyan. Non-RVD residues at the 4th and 32nd positions are presented as bold letters with different colours for the mutation sites. The secondary structures are presented at the bottom. (b) Ribbon representations of a single-TAL repeat (left) and the DNA bound TALE protein (right) (PDBID: 3V6T¹⁴). The first short helix (helix a) and the second long helix (helix b) are coloured red and green, respectively. RVD and the periodical mutation sites are noted in cyan and magenta, respectively, with the side chains shown as a stick representation. In the right panel, RVDs and the mutation sites are also displayed. DNA is also presented in orange. Figures were prepared using PyMOL (DeLano Scientific, San Carlos, CA). (c) Schematic representation of CT-TALE (upper) and VT-TALE (lower). TAL-repeats are represented as yellow boxes. Non-canonical pseudo-repeats¹² and the last half repeats³⁰ are presented as dashed boxes and white boxes, respectively. Amino acid types of non-RVD residues at the 4th and 32nd positions in each repeat are given as letters; mutated sites are coloured.