Figure 5.
The β-propeller structure of the TYW4 C-terminal domain (TYW4C). (A) and (B) Top and front views of ribbon representations of TYW4C (A) and the Keap1 Kelch domain (PDB ID: 1U6D) (31) (B). The protein main chain is colored as in Figure 2. (C) Structure-based sequence alignment of the six Kelch repeat motifs from Keap1 (upper) and TYW4 (lower). The four β strands are labeled a–b. The Arg residues involved in the interactions are boxed. Key signature residues seen in typical Kelch repeats (see text) are indicated with arrows. Structural alignments were calculated with SSM (43). (D) Interactions between TYW4N and TYW4C. The protein main chain is shown in a ribbon representation, with the same coloring scheme as in Figure 2. The protein side chains that are conserved and involved in the interaction are shown with stick models. (E) Interactions between Keap1 and the Neh2 peptide (PDB ID: 1X2R) (34). The main chain of the protein and bound peptide are shown with ribbon representations. The side chains that are conserved and involved in the interaction are shown with stick models.