Fig. 2.

The loop-less Mad2 (Mad2^LL) forms the I-Mad2–C-Mad2 dimer. (A) Superimposed diagrams of the Mad2^ΔN dimer (with its I-Mad2 and C-Mad2 monomers colored in purple and blue, respectively) and the Mad2^LL dimer (with its I-Mad2 and C-Mad2–MBP1 monomers colored gray and green, respectively). C-tail, the C-terminal tail of Mad2; MBP1, Mad2 binding peptide 1, an unnatural peptide ligand of Mad2 identified through phage display. (B) Overlay of the methyl region of the ¹H/¹³C HSQC spectra of ¹³C-labeled O-Mad2^LL (black) and ¹³C-labeled I-Mad2^LL bound to unlabeled C-Mad2–MBP1 complex (blue). (C) Overlay of the methyl region of the ¹H/¹³C HSQC spectra of ¹³C-labeled I-Mad2^ΔC bound to unlabeled C-Mad2–MBP1 complex (red) and ¹³C-labeled I-Mad2^LL bound to unlabeled C-Mad2–MBP1 complex (blue).