Comparison of D4β_c with the membrane-proximal domain of GHR.

D4β_c and domain 2 of the subunit of the GHR, which interacts with the helix A/helix C face of GH, were aligned structurally via their core residues and are shown as surface representations using the program InsightII (MSI, San Diego, CA). The hydrophobic-aromatic patch, H2, of D4β_c and the location of GHR that interacts with the opposing receptor molecule are indicated by green surfaces. The red surfaces of D4β_c indicate the residues required for affinity-conversion, and the blue surfaces of GHR indicate the region known to interact with GH.