7PXE image
Entry Detail
PDB ID:
7PXE
EMDB ID:
Title:
Ca2+ bound Drosophila Slo channel
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2021-10-08
Release Date:
2021-12-15
Method Details:
Experimental Method:
Resolution:
2.38 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Isoform J of Calcium-activated potassium channel slowpoke
Chain IDs:A, B, C, D
Chain Length:1180
Number of Molecules:4
Biological Source:Drosophila melanogaster
Primary Citation
Small molecule modulation of the Drosophila Slo channel elucidated by cryo-EM.
Nat Commun 12 7164 7164 (2021)
PMID: 34887422 DOI: 10.1038/s41467-021-27435-w

Abstact

Slowpoke (Slo) potassium channels display extraordinarily high conductance, are synergistically activated by a positive transmembrane potential and high intracellular Ca2+ concentrations and are important targets for insecticides and antiparasitic drugs. However, it is unknown how these compounds modulate ion translocation and whether there are insect-specific binding pockets. Here, we report structures of Drosophila Slo in the Ca2+-bound and Ca2+-free form and in complex with the fungal neurotoxin verruculogen and the anthelmintic drug emodepside. Whereas the architecture and gating mechanism of Slo channels are conserved, potential insect-specific binding pockets exist. Verruculogen inhibits K+ transport by blocking the Ca2+-induced activation signal and precludes K+ from entering the selectivity filter. Emodepside decreases the conductance by suboptimal K+ coordination and uncouples ion gating from Ca2+ and voltage sensing. Our results expand the mechanistic understanding of Slo regulation and lay the foundation for the rational design of regulators of Slo and other voltage-gated ion channels.

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Primary Citation of related structures