Fig. 3.

Structure-based sequence alignment of three subdomains of the C-terminal domain. The darker shades represent higher, and lighter shades lower levels of sequence similarity. The secondary structure elements are shown underneath the sequence, where blue arrows correspond to β-stands, and orange rectangles to α-helices. Amino acids corresponding to the D-X-G-S/T-G-X₃-D motif are boxed in red, with the sequence logo below. Identical residues are marked by the red arrows. Each motif is composed of nine residues numbered 1–9; the four N-terminally preceding positions are numbered from −4 to −1, accordingly.