Fig. 4

Sequence alignment and structural comparison of GDF8 and GDF11 in their FS288-bound state. a Sequence alignment of mature GDF8 and GDF11. Secondary structure for each ligand in the FS288-bound form is shown above and below the GDF8 and GDF11 sequences, respectively, where arrows represent β-sheet and cylinders represent α-helix. Cysteines are highlighted in yellow, and residues that are different between GDF8 and GDF11 are highlighted in blue. Solid black lines joining two cysteines indicate intramolecular disulfide bonds. The dotted black line indicates the cysteine responsible for the intermolecular disulfide bond. b Distribution of the amino acid differences between GDF8 and GDF11. GDF11 is shown as ribbon, and non-identical amino acids are shown as orange spheres. Symmetrical type I and type II interfaces are depicted with blue and yellow lines (left). Insets represent zoomed-in views depicting the molecular differences between FS288-bound GDF8 (blue) and FS288-bound GDF11 (orange) in the vicinity of the type I receptor binding interface. The arrow points to the hydrogen bond (dotted line) in the FS288-bound GDF11 between Q62 and carbonyl oxygen of Y49 (middle)