Sequence identity and conservation of residues in glutamate receptor subunits
Numbers are the percentage of residues in the regions that are identical in all subunits within the group. Numbers in parenthesis are the percentage of residues that are identical in 50% of the subunits in the group (i.e., conserved). ATD includes the signal peptide, M1M2M3 includes pre-M1 and intracellular loops, LBD is S1 and S2. TMD is M1M2M3 and M4. In GluA2, the regions were defined as amino acids 1–397 (signal peptide and ATD), 398–414 (ATD-S1 linker), 415–527 (S1), 528–534 (S1-M1 linker), 535–647 (M1M2M3), 648–652 (M3-S2 linker), 653–794 (S2), 795–809 (S2-M4 linker), 810–838 (M4) and 839–884 (CTD) using the structures of the isolated GluA2 LBD (Armstrong and Gouaux, 2000) and the membrane-spanning tetrameric GluA2 (Sobolevsky et al., 2009) as guides.
| Receptor Subunits | ATD | S1 | S2 | LBD | M1M2M3 | M4 | TMD | CTD | All |
|---|---|---|---|---|---|---|---|---|---|
| GluA1–4 | 35 (89) | 74 (99) | 84 (100) | 80 (100) | 84 (97) | 93 (100) | 87 (98) | 9 (60) | 54 (90) |
| GluK1–5 | 16 (67) | 54 (89) | 53 (94) | 53 (92) | 60 (96) | 41 (97) | 56 (96) | 0.0 (13) | 29 (70) |
| GluA1–4, GluK1–5 | 6 (36) | 37 (81) | 33 (77) | 34 (79) | 45 (78) | 28 (62) | 42 (77) | 0.0 (3) | 17 (48) |
| GluN1, GluN2A-D, GluN3A-B | 1 (24) | 19 (61) | 18 (76) | 19 (68) | 16 (81) | 10 (83) | 14 (81) | 0.0 (2.9) | 5 (29) |
| GluN2A-D | 19 (76) | 60 (94) | 66 (99) | 63 (96) | 75 (99) | 69 (100) | 73 (99) | 2 (47) | 25 (70) |
| GluD1–2 | 60 (60) | 67 (67) | 57 (57) | 62 (62) | 51 (51) | 62 (62) | 54 (54) | 34 (34) | 54 (54) |
| All subunits | 0.2 (15) | 7 (49) | 6 (48) | 6 (48) | 10 (55) | 10 (52) | 10 (55) | 0.0 (0.2) | 2 (19) |