5u76

Chicken Slo2.2 in a closed conformation vitrified in the presence of 300 mM NaClChicken Slo2.2 in a closed conformation vitrified in the presence of 300 mM NaCl

5u76, resolution 4.20Å Show:Asymmetric Unit Biological Assembly Structural highlights 5u76 is a 1 chain structure with sequence from Chick. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 5u70 Gene: KCNT1, SLACK (CHICK) Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [KCNT1_CHICK] Generates outwardly rectifying currents that are suppressed by elevation of intracellular calcium. Publication Abstract from PubMed The stable structural conformations that occur along the complete reaction coordinate for ion channel opening have never been observed. In this study, we describe the equilibrium ensemble of structures of Slo2.2, a neuronal Na+-activated K+ channel, as a function of the Na+ concentration. We find that Slo2.2 exists in multiple closed conformations whose relative occupancies are independent of Na+ concentration. An open conformation emerges from an ensemble of closed conformations in a highly Na+-dependent manner, without evidence of Na+-dependent intermediates. In other words, channel opening is a highly concerted, switch-like process. The midpoint of the structural titration matches that of the functional titration. A maximum open conformation probability approaching 1.0 and maximum functional open probability approaching 0.7 imply that, within the class of open channels, there is a subclass that is not permeable to ions. Structural Titration of Slo2.2, a Na+-Dependent K+ Channel.,Hite RK, MacKinnon R Cell. 2017 Jan 26;168(3):390-399.e11. doi: 10.1016/j.cell.2016.12.030. Epub 2017 , Jan 19. PMID:28111072 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Potassium channel 3D structures