Structure of cdb3 tetramer.

(A) The packing of selected cdb3 dimers in the crystal illustrated schematically by projection onto an a, c plane of the unit cell. The unit cell includes 4 monomers of types P, Q, R, and S. (B) The association of cdb3 subunits in the likely physiological tetramer, with each potential ankyrin binding loop (residues 176-190) highlighted in red. The plane of the bilayer is believed to lie in a horizontal plane at the top of the diagram. (C) Relative orientation of the truncated N- and C-termini of the tetramer, as viewed from one end of the tetramer. Color coding is the same as in Figure 3B. Panels A and B are rotated with respect to each other by 180° about a horizontal axis in the plane of the page.