How conserved are IML3 interfacing residues?
Most of IML3:CHL4 conserved residues lay on a single large patch
A large cluster of highly conserved residues on IML3 interacts with CHL4 by "grabbing" one of the projections that compose CHL4's characteristic "U" groove.
The larger cluster includes the H-bond-forming GLU164, indicating the importance of a polar residue in this interface.
Summary of conserved residue on the IML3:CTF3 interface. (pink - conserved; white and blue - not conserved). CTF3 is shown as a green surface.
IML3 has a conserved "bulge" that fits into CTF3
Most of the IML3 residues that interface with CTF3 are conserved in a bulging section that fits into a concave region on CTF3.
Although the conserved residues do not appear to participate directly in the formation of contact bonds, they may aid interactions by shape complementarity.
Additionally, the residues are mostly polar.