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-Structure paper
Title | Cytoplasmic domain structures of Kir2.1 and Kir3.1 show sites for modulating gating and rectification. |
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Journal, issue, pages | Nat Neurosci, Vol. 8, Issue 3, Page 279-287, Year 2005 |
Publish date | Feb 20, 2005 |
Authors | Scott Pegan / Christine Arrabit / Wei Zhou / Witek Kwiatkowski / Anthony Collins / Paul A Slesinger / Senyon Choe / |
PubMed Abstract | N- and C-terminal cytoplasmic domains of inwardly rectifying K (Kir) channels control the ion-permeation pathway through diverse interactions with small molecules and protein ligands in the cytoplasm. ...N- and C-terminal cytoplasmic domains of inwardly rectifying K (Kir) channels control the ion-permeation pathway through diverse interactions with small molecules and protein ligands in the cytoplasm. Two new crystal structures of the cytoplasmic domains of Kir2.1 (Kir2.1(L)) and the G protein-sensitive Kir3.1 (Kir3.1(S)) channels in the absence of PIP(2) show the cytoplasmic ion-permeation pathways occluded by four cytoplasmic loops that form a girdle around the central pore (G-loop). Significant flexibility of the pore-facing G-loop of Kir2.1(L) and Kir3.1(S) suggests a possible role as a diffusion barrier between cytoplasmic and transmembrane pores. Consistent with this, mutations of the G-loop disrupted gating or inward rectification. Structural comparison shows a di-aspartate cluster on the distal end of the cytoplasmic pore of Kir2.1(L) that is important for modulating inward rectification. Taken together, these results suggest the cytoplasmic domains of Kir channels undergo structural changes to modulate gating and inward rectification. |
External links | Nat Neurosci / PubMed:15723059 |
Methods | X-ray diffraction |
Resolution | 2.09 - 2.41 Å |
Structure data | PDB-1u4e: PDB-1u4f: |
Chemicals | ChemComp-HOH: |
Source |
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Keywords | METAL TRANSPORT / ALLERGEN / cytoplasmic domain / Kir2.1 / IRK1 / inwardly rectifying K channel / rectification |