Figure 65.

Synthetic symmetrization via Cys residues introduced by mutagenesis. a) Illustration of synthetic symmetrization. An asymmetric protein monomer is represented by the figure “5.” Cys residues introduced at different positions on the surface are shown in yellow. Dimerization is achieved via disulfide bond formation. Trimerization requires a trivalent mediator. b) Illustration of the approach using CelA. Eight positions were selected for mutation to Cys. c) Interface for disulfide-bonded monomers of the D188C variant obtained by XRD. Very few contacts, other than the disulfide bond, are observed. d) Crystal packing of the D188C dimer. Adapted with permission from Ref.⁵⁰⁸. Copyright 2011 Wiley.