2QTO
An anisotropic model for potassium channel KcsA
Summary for 2QTO
| Entry DOI | 10.2210/pdb2qto/pdb |
| Related | 1BL8 |
| Descriptor | Voltage-gated potassium channel, POTASSIUM ION (3 entities in total) |
| Functional Keywords | potassium channel, membrane proteins, normal-mode refinement, anisotropic thermal factors, metal transport, membrane protein |
| Biological source | Streptomyces lividans |
| Cellular location | Cell membrane; Multi-pass membrane protein: P0A334 |
| Total number of polymer chains | 4 |
| Total formula weight | 41129.13 |
| Authors | Chen, X.,Poon, B.K.,Dousis, A.,Wang, Q.,Ma, J. (deposition date: 2007-08-02, release date: 2007-09-25, Last modification date: 2023-08-30) |
| Primary citation | Chen, X.,Poon, B.K.,Dousis, A.,Wang, Q.,Ma, J. Normal-mode refinement of anisotropic thermal parameters for potassium channel KcsA at 3.2 A crystallographic resolution Structure, 15:955-962, 2007 Cited by PubMed Abstract: We report a normal-mode method for anisotropic refinement of membrane-protein structures, based on a hypothesis that the global near-native-state disordering of membrane proteins in crystals follows low-frequency normal modes. Thus, a small set of modes is sufficient to represent the anisotropic thermal motions in X-ray crystallographic refinement. By applying the method to potassium channel KcsA at 3.2 A, we obtained a structural model with an improved fit with the diffraction data. Moreover, the improved electron density maps allowed for large structural adjustments for 12 residues in each subunit, including the rebuilding of 3 missing side chains. Overall, the anisotropic KcsA structure at 3.2 A was systematically closer to a 2.0 A KcsA structure, especially in the selectivity filter. Furthermore, the anisotropic thermal ellipsoids from the refinement revealed functionally relevant structural flexibility. We expect this method to be a valuable tool for structural refinement of many membrane proteins with moderate-resolution diffraction data. PubMed: 17698000DOI: 10.1016/j.str.2007.06.012 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (3.201 Å) |
Structure validation
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