Figure 3.

Mimicyp self-associates in solution. Removing mimicyp residues that form X-ray crystal contacts shifts the equilibrium toward the monomeric state in solution, as evidenced by ¹H-¹⁵N TROSY-HSQC spectra collected at 25 °C at 600 MHz. (a) The full length wild-type mimicyp (blue spectrum) only gives rise to a subset of resonances, most likely emanating from flexible loop regions. (b) The mutant mimicyp Δ188-194 (green spectrum) cannot form trimer interactions, since the basic residues of 188–194 have been replaced with the sequence SGSSG. (c) The mutant Δ206-234 (pink spectrum) cannot form trimer–trimer interactions that are mediated in part by the C-terminal residues.