Figure 1: Origins of ionotropic glutamate receptors (iGluRs).
From: A modern ionotropic glutamate receptor with a K+ selectivity signature sequence
(a) Transmembrane (TM) and domain organization of iGluRs, AvGluR1 and proteins resembling bacterial ancestors. Colour shading is based on sequence identities of individual domains (also see Supplementary Table S1). (b) Sequence alignment of pore loop and TM2 for AvGluR1, iGluRs from mammals and plants, and GluR0 and K+ channels. Residues found in at least three sequences are highlighted in bold. Colours highlight conserved motifs. NTD, N-terminal domain; PPBP, periplasmic binding protein.
