Amino acid sequences of the selectivity filters of different NaV and CaV channels
| Channel . | Locus EEEE . | Locus DCS . |
|---|---|---|
| HsCaV1.1 | EEEE | DSQE |
| HsCaV1.2 | EEEE | DSED |
| HsCaV2.1 | EEEE | DEQN |
| HsCaV2.2 | EEEE | DAME |
| HsCaV2.3 | EEEE | TEQE |
| HsCaV3.1 | EEDD | DVNG |
| Am-CaV4 | DEEA | DEED |
| DSC1 | DEEA | NEED |
| BSC1 | DEEA | NEED |
| Am-NaV | DEKA | NEQG |
| Channel . | Locus EEEE . | Locus DCS . |
|---|---|---|
| HsCaV1.1 | EEEE | DSQE |
| HsCaV1.2 | EEEE | DSED |
| HsCaV2.1 | EEEE | DEQN |
| HsCaV2.2 | EEEE | DAME |
| HsCaV2.3 | EEEE | TEQE |
| HsCaV3.1 | EEDD | DVNG |
| Am-CaV4 | DEEA | DEED |
| DSC1 | DEEA | NEED |
| BSC1 | DEEA | NEED |
| Am-NaV | DEKA | NEQG |
The EEEE locus is the locus responsible for divalent/monovalent selectivity, while the DCS (divalent cation selectivity) is the locus responsible for the selectivity between divalent cations (Ba2+, Ca2+, Sr2+) (Cens et al., 2007). For CaV4, Am-NaV, DSC1, and BSC1 the location of the DCS locus is taken relative to the conserved tryptophan in each pore domain.