Fig. 3.

A) Top-view of the RDL GABA-R homo-pentamer (Nl RDL homology model based on 3RHW) showing three subunits in yellow, one in green and red, respectively. The mutation site A301S is located in the middle of the M2 transmembrane helices forming the channel pore. The other mutation site Q359E is located intracellularly at the end of helix M3 outside the pore region (indicated by an arrow). B) Side-view showing two of the RDL subunits and the location of the mutation site A301S in transmembrane pore helix M2, whereas mutation site Q359E is located > 40 Å from this residue (the helical structure of the domain is proposed as amino acid positions 337–428 are missing in the modelling template 3RHW).