Fig. 1: GlyR-loop stabilizes GephE dimerization within gephyrin trimer.
From: Gephyrin filaments represent the molecular basis of inhibitory postsynaptic densities
a Gephyrin trimer domain structure overview showing G-domain (GephG), C-domain (GephC) and E-domain (GephE). The respective crystal structures of GephG (green, PDB: 1JLJ) and GephE (blue, PDB 2FU3) are shown in cartoon representation with faded surfaces and size indicators. A graphical representation of the full-length gephyrin trimer is depicted (middle panel). b Cartoon representation of isolated GephE dimer in complex with GlyR-loop (PDB: 2FTS), highlighting subdomain (SD) division (color code: SDI: red; SDII: green; SDIII: yellow; SDIV: blue) and position of GlyR-loop (orange). The second monomer is shown in gray. Positions of G375 and D422 in SDII are highlighted (magenta). c Representative 2D class averages of isolated Geph trimer following negative stain SPA showing GephE with GephG (c1), isolated GephE (c2) and undefinable densities (c3). The pie chart indicates the relative distribution of particles throughout the 2D class averages. d Surface representation of final map using particles from classes with GephE + GephG (c1). GephE dimer (PDB 2FU3, blue) and GephG trimer (PDB: 1JLJ, green) shown in cartoon representation were rigid-body fitted into the respective densities in the map. Scale bar: 50 Å. e Representative 2D class averages of isolated Geph trimer in complex with GlyR-loop after negative stain SPA showing GephE with GephG (e1), isolated GephE (e2), complex of two GephE dimers (e3) and undefinable densities (e4). The pie chart indicates the relative distribution of particles throughout the 2D class averages. f Surface representation of final map using particles from classes with GephE + GephG (e1). GephE dimer (PDB 2FU3, blue) and GephG trimer (PDB: 1JLJ, green) shown in cartoon representation were rigid-body fitted into the respective densities in the map. g Surface representation of final map using particles from classes with GephE + GephE complex (e3). Two consecutive GephE dimers shown in cartoon representation (PDB 2FU3, blue) were rigid body fitted into the respective densities in the map. Scale bar 50 Å. Cartoon bar diagrams illustrate the Geph constructs used in this experiment (green: GephG, gray: GephC, light green: SDII, red: position of amino acid substitution, orange: GlyR-loop).
