5VMS
CryoEM structure of Xenopus KCNQ1 channel
Summary for 5VMS
| Entry DOI | 10.2210/pdb5vms/pdb |
| EMDB information | 8712 |
| Descriptor | Potassium voltage-gated channel subfamily KQT member 1, Calmodulin, CALCIUM ION (3 entities in total) |
| Functional Keywords | kcnq1-cam complex, potassium channel, long qt syndrome, transport protein, calcium binding protein |
| Biological source | Xenopus laevis (African clawed frog) More |
| Total number of polymer chains | 2 |
| Total formula weight | 79636.18 |
| Authors | Mackinnon, R.,Sun, J. (deposition date: 2017-04-28, release date: 2017-06-07, Last modification date: 2024-03-13) |
| Primary citation | Sun, J.,MacKinnon, R. Cryo-EM Structure of a KCNQ1/CaM Complex Reveals Insights into Congenital Long QT Syndrome. Cell, 169:1042-1050.e9, 2017 Cited by PubMed Abstract: KCNQ1 is the pore-forming subunit of cardiac slow-delayed rectifier potassium (I) channels. Mutations in the kcnq1 gene are the leading cause of congenital long QT syndrome (LQTS). Here, we present the cryoelectron microscopy (cryo-EM) structure of a KCNQ1/calmodulin (CaM) complex. The conformation corresponds to an "uncoupled," PIP-free state of KCNQ1, with activated voltage sensors and a closed pore. Unique structural features within the S4-S5 linker permit uncoupling of the voltage sensor from the pore in the absence of PIP. CaM contacts the KCNQ1 voltage sensor through a specific interface involving a residue on CaM that is mutated in a form of inherited LQTS. Using an electrophysiological assay, we find that this mutation on CaM shifts the KCNQ1 voltage-activation curve. This study describes one physiological form of KCNQ1, depolarized voltage sensors with a closed pore in the absence of PIP, and reveals a regulatory interaction between CaM and KCNQ1 that may explain CaM-mediated LQTS. PubMed: 28575668DOI: 10.1016/j.cell.2017.05.019 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.7 Å) |
Structure validation
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