3stl

KcsA potassium channel mutant Y82C with Cadmium bound

spinqualitylabelsall models 3stl, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3stl 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. Ligands: CD, K Related: 3stz Resources: FirstGlance, OCA, RCSB, PDBsum 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 In K(+) channels, rearrangements of the pore outer vestibule have been associated with C-type inactivation gating. Paradoxically, the crystal structure of Open/C-type inactivated KcsA suggests these movements to be modest in magnitude. In this study, we show that under physiological conditions, the KcsA outer vestibule undergoes relatively large dynamic rearrangements upon inactivation. External Cd(2+) enhances the rate of C-type inactivation in an cysteine mutant (Y82C) via metal-bridge formation. This effect is not present in a non-inactivating mutant (E71A/Y82C). Tandem dimer and tandem tetramer constructs of equivalent cysteine mutants in KcsA and Shaker K(+) channels demonstrate that these Cd(2+) metal bridges are formed only between adjacent subunits. This is well supported by molecular dynamics simulations. Based on the crystal structure of Cd(2+)-bound Y82C-KcsA in the closed state, together with electron paramagnetic resonance distance measurements in the KcsA outer vestibule, we suggest that subunits must dynamically come in close proximity as the channels undergo inactivation. Mechanism of Cd(2+) Coordination during Slow Inactivation in Potassium Channels.,Raghuraman H, Cordero-Morales JF, Jogini V, Pan AC, Kollewe A, Roux B, Perozo E Structure. 2012 Aug 8;20(8):1332-42. Epub 2012 Jul 5. PMID:22771214 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Antibody

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