5e1a

Structure of KcsA with L24C/R117C mutations

spinqualitylabelsall models 5e1a, resolution 3.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5e1a is a 3 chain structure with sequence from Mus musculus and Streptomyces lividans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.4Å Ligands: K Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function KCSA_STRLI Acts as a pH-gated potassium ion channel; changing the cytosolic pH from 7 to 4 opens the channel, although it is not clear if this is the physiological stimulus for channel opening. Monovalent cation preference is K(+) > Rb(+) > NH4(+) >> Na(+) > Li(+). Publication Abstract from PubMed The process of ion channel gating-opening and closing-involves local and global structural changes in the channel in response to external stimuli. Conformational changes depend on the energetic landscape that underlies the transition between closed and open states, which plays a key role in ion channel gating. For the prokaryotic, pH-gated potassium channel KcsA, closed and open states have been extensively studied using structural and functional methods, but the dynamics within each of these functional states as well as the transition between them is not as well understood. In this study, we used solution nuclear magnetic resonance (NMR) spectroscopy to investigate the conformational transitions within specific functional states of KcsA. We incorporated KcsA channels into lipid bicelles and stabilized them into a closed state by using either phosphatidylcholine lipids, known to favor the closed channel, or mutations designed to trap the channel shut by disulfide cross-linking. A distinct state, consistent with an open channel, was uncovered by the addition of cardiolipin lipids. Using selective amino acid labeling at locations within the channel that are known to move during gating, we observed at least two different slowly interconverting conformational states for both closed and open channels. The pH dependence of these conformations and the predictable disruptions to this dependence observed in mutant channels with altered pH sensing highlight the importance of conformational heterogeneity for KcsA gating. Conformational heterogeneity in closed and open states of the KcsA potassium channel in lipid bicelles.,Kim DM, Dikiy I, Upadhyay V, Posson DJ, Eliezer D, Nimigean CM J Gen Physiol. 2016 Aug;148(2):119-32. doi: 10.1085/jgp.201611602. Epub 2016 Jul , 18. PMID:27432996 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Antibody 3D structures Potassium channel 3D structures 3D structures of non-human antibody

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