Fig. 1

Fig. 1

a Domain organization of Gpr126, indicating the ECR and 7TM regions. The unknown region includes a splice site. Cleavage sites (furin cleavage, autoproteolysis) are indicated by dashed lines. Domains are colored dark blue (CUB), cyan (PTX), gray (unknown region), yellow (HormR), red (GAIN), and purple (7TM). Domain boundaries are indicated below. SP indicates signal peptide. b Structure of the full ECR of (−ss) Gpr126. Domains are colored as in a except for the newly identified SEA domain (green). Domains are numbered (1–5) from N to C-terminus. Calcium ion in CUB domain is indicated as a green sphere. Dashed lines represent disordered residues. N-linked glycans are shown as green sticks. c Schematic of full-length Gpr126. The previously unknown region (SEA domain and linker region) is labeled. Autoproteolysis in GAIN domain is indicated by an asterisk and the last beta-strand of the GAIN domain is colored gray. d Representative negative-stain EM 2D class average of Gpr126 (−ss) ECR. Scale bar (white) represents 50 Å. Domains are assigned and colored according to color scheme noted above. The dashed line represents the linker region.