FIGURE 8.

Alp12 interactions. A and B, charged interaction surfaces within the Alp12 protofilament. The two views are tilted relative to each other to see the electrostatic interactions at the interface. In particular, subdomain 2 of the lower monomer offers an acidic surface to a basic region on subdomain 1 of the upper monomer. C, Alp12 arrangement of three monomers within a parallel strand. D, three monomers within F-actin whereby the dark green monomer is in the same orientation as the orange Alp12 monomer in C. Alp12 uses different surfaces to form a strand from two protofilaments.