Fig. 7.
Multidomain model of Ca2+influx in NMDAR channels. A schematic of the determinants of Ca2+ influx in NMDAR channels is shown. The M2 loop and M3 are indicated as thick lines. The narrow constriction is positioned at the approximate tip of the M2 loop and at the approximate center of the pore (Villarroel et al., 1995; Zarei and Dani, 1995). It is also formed by asparagines occupying nonhomologous positions, the NR2 N+1 site, and the NR1 N site (Wollmuth et al., 1996). Residues in DRPEER that are apparently exposed to the water interface are shown as open circles.