Left, localization of interface 1 between GluN1 ABD and GluN2B NTD. This interface involves a GluN1 specific loop that protrudes from GluN1 ABD upper lobe towards GluN2B NTD lower lobe. Right, Initial and final frames of the fitting presented in Fig 4 at interface 1. The two pairs of residues targeted for cysteine mutations GluN1-N492/GluN2B-S188 and GluN1-K495/GluN2B-N192 are shown as spheres linked by a dotted line colored black and red, respectively 