Fig. 1: Crystallographic evidence for a decameric assembly of zGDNF-zGFRα1^D2-D3.

a Domain organisation for zGFRα1^D2-D3 and zGDNF^mat with discrete colours for individual domains. b Orthogonal views of the zGFRα1^D2-D3-zGDNF^mat assembly crystal structure. Domains are coloured according to (a), zGFRα1-D2, light green, zGFRα1-D3 dark green, GDNF dimer protomers yellow and orange. N-glycans attached to zGDNF and zGFRα1-D3 are shown as sticks. Bottom view projects directly down the five-fold rotational symmetry axis. c zGFRα1 interface between each subunit of the pentameric ring, opened to highlight secondary structure elements and interacting residues at the site of contact. Main chain atoms are shown as a cartoon and interaction residues as sticks. A transparent surface (green) and interaction surface (purple) are also shown. d Close up view of the zGFRα1 pentameric interface with key interacting residues shown as sticks with hydrogen-bonds displayed as dashed lines. e Schematic model for zGDNF^mat zGFRα1^D2-D3 decameric complex assembly in vitro. The model emphasises a 2:2 zGDNF^mat-zGFRα1^D2-D3 complex intermediate that multimerises through GFRα1 homophilic interactions.