Fig. 2.

α^43a–α^43a interactions. (A) Self-association of α^43a molecules in trans configuration showing interfaces 1 and 1′. A close-up view of the packing interface is shown; each interface contains nine hydrogen bonds [N29–T256 (two hydrogen bonds), N60–T256, N60–T237, D79–T237, N96–R200, T97–R200, T98–R200, G115–R200] and a salt bridge between the R59 and E216 side chains. (B) Close-up view of the packing interface of modeled α^43b molecules indicating the predicted hydrogen-bond interactions (D29–T255, R59–N215, N60–T236, N60–T255, D79–T236, S78–N215, T97–R199, G114–R199). The α^43b interface residues that are not conserved in α^43a are colored in magenta.