3STZ
KcsA potassium channel mutant Y82C with nitroxide spin label
Summary for 3STZ
| Entry DOI | 10.2210/pdb3stz/pdb |
| Related | 3STL |
| Descriptor | antibody Fab fragment heavy chain, antibody Fab fragment light chain, Voltage-gated potassium channel, ... (6 entities in total) |
| Functional Keywords | transmembrane protein, ion channel, kcsa potassium channel, inactivation, spin-label, membrane protein |
| Biological source | Streptomyces lividans More |
| Cellular location | Cell membrane; Multi-pass membrane protein: P0A334 |
| Total number of polymer chains | 3 |
| Total formula weight | 58148.50 |
| Authors | Raghuraman, H.,Cordero-Morales, J.,Jogini, V.,Perozo, E. (deposition date: 2011-07-11, release date: 2012-04-18, Last modification date: 2012-10-03) |
| Primary citation | Raghuraman, H.,Cordero-Morales, J.F.,Jogini, V.,Pan, A.C.,Kollewe, A.,Roux, B.,Perozo, E. Mechanism of Cd(2+) Coordination during Slow Inactivation in Potassium Channels. Structure, 20:1332-1342, 2012 Cited by PubMed Abstract: 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 Cd2+ 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 Cd2+ metal bridges are formed only between adjacent subunits. This is well supported by molecular dynamics simulations. Based on the crystal structure of Cd2+ -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. PubMed: 22771214DOI: 10.1016/j.str.2012.03.027 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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