Figure 4.

Binding orientation (A) of interacting pairs of helices for trimer structures in compact (B) and linear shape (C), characterized by the probability distribution (artificial units) of relative binding positions (β) and (χ) for the WT. The x and y axes in (A) were arbitrarily chosen. The dominant binding interface (I-c1) as well as alternative binding interfaces are marked by white and yellow arrows. The alternative binding interfaces show a moderate shift for the packing in compact trimers, whereas the same interaction surfaces were found for linear trimers as compared to those previously reported for a dimer ensemble (33). To see this figure in color, go online.