Fig. 2.

Residues that are homologous to known determinants of ifenprodil binding. A, color-coded model of the conservation found between the GluN2A-D subunits. Blue represents identical residues, whereas red shows similar residues. Note the high conservation in the LBD-TM (transmembrane) region compared with the lower conservation within the ATD region. B, two-dimensional illustration of the most important interactions formed between the GluN1/GluN2B interface and ifenprodil. A table gives the GluN2B residues that interact with ifenprodil and corresponding residues within the other GluN2 subtypes. C, summary of the sequence similarity between the different GluN2 subunits.