Fig. 6: Ligand recognition in the insulin superfamily.
From: Ligand recognition mechanism of the human relaxin family peptide receptor 4 (RXFP4)
a Sequence alignment (left) and structure superimposition (right) of peptides in the insulin superfamily colored as the labels. b–d Recognition of INSL5 (b) insulin (PDB code: 6PXW) (c) and IGF-1 (PDB code: 6PYH) (d) by cognate receptors, where the peptide (green) and receptor (grey) are shown in cartoon and surface, respectively. The peptide segments responsible for recognition are highlighted in the pink-shaded region and the three disulfide bonds in each peptide are indicated by yellow solid lines. e Distinct ligand recognition modes in the insulin superfamily.
