6BY2
Closed and deep-inactivated conformation of KcsA-T75A mutant
Summary for 6BY2
Entry DOI | 10.2210/pdb6by2/pdb |
Descriptor | Antibody Heavy Chain, Antibody Light Chain, pH-gated potassium channel KcsA, ... (7 entities in total) |
Functional Keywords | kcsa, c-type inactivation, ion channel, potassium channel, membrane protein |
Biological source | Mus musculus More |
Total number of polymer chains | 3 |
Total formula weight | 58682.26 |
Authors | Labro, A.J.,Cortes, D.M.,Tilegenova, C.,Cuello, L.G. (deposition date: 2017-12-19, release date: 2018-05-09, Last modification date: 2024-11-06) |
Primary citation | Labro, A.J.,Cortes, D.M.,Tilegenova, C.,Cuello, L.G. Inverted allosteric coupling between activation and inactivation gates in K+channels. Proc. Natl. Acad. Sci. U.S.A., 115:5426-5431, 2018 Cited by PubMed Abstract: The selectivity filter and the activation gate in potassium channels are functionally and structurally coupled. An allosteric coupling underlies C-type inactivation coupled to activation gating in this ion-channel family (i.e., opening of the activation gate triggers the collapse of the channel's selectivity filter). We have identified the second Threonine residue within the TTVGYGD signature sequence of K channels as a crucial residue for this allosteric communication. A Threonine to Alanine substitution at this position was studied in three representative members of the K-channel family. Interestingly, all of the mutant channels exhibited lack of C-type inactivation gating and an inversion of their allosteric coupling (i.e., closing of the activation gate collapses the channel's selectivity filter). A state-dependent crystallographic study of KcsA-T75A proves that, on activation, the selectivity filter transitions from a nonconductive and deep C-type inactivated conformation to a conductive one. Finally, we provide a crystallographic demonstration that closed-state inactivation can be achieved by the structural collapse of the channel's selectivity filter. PubMed: 29735651DOI: 10.1073/pnas.1800559115 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.35 Å) |
Structure validation
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