6NFV

Structure of the KcsA-G77C mutant or the 2,4-ion bound configuration of a K+ channel selectivity filter.

Summary for 6NFV

• Entry DOI: 10.2210/pdb6nfv/pdb
• Descriptor: antibody fragment heavy chain, antibody fragment light chain, pH-gated potassium channel KcsA, ... (7 entities in total)
• Functional Keywords: ion channel, membrane transport, potassium channel, membrane protein, metal transport
• Biological source: Mus musculus; More
• Total number of polymer chains: 3
• Total formula weight: 58615.13

Authors

Tilegenova, C.,Cortes, D.M.,Jahovic, N.,Hardy, E.,Parameswaran, H.,Guan, L.,Cuello, L.G. (deposition date: 2018-12-20, release date: 2019-08-07, Last modification date: 2019-12-18)

Primary citation

Tilegenova, C.,Cortes, D.M.,Jahovic, N.,Hardy, E.,Hariharan, P.,Guan, L.,Cuello, L.G.
Structure, function, and ion-binding properties of a K+channel stabilized in the 2,4-ion-bound configuration.
Proc.Natl.Acad.Sci.USA, 116:16829-16834, 2019

PubMed Abstract: Here, we present the atomic resolution crystallographic structure, the function, and the ion-binding properties of the KcsA mutants, G77A and G77C, that stabilize the 2,4-ion-bound configuration (i.e., water, K, water, K-ion-bound configuration) of the K channel's selectivity filter. A full functional and thermodynamic characterization of the G77A mutant revealed wild-type-like ion selectivity and apparent K-binding affinity, in addition to showing a lack of C-type inactivation gating and a marked reduction in its single-channel conductance. These structures validate, from a structural point of view, the notion that 2 isoenergetic ion-bound configurations coexist within a K channel's selectivity filter, which fully agrees with the water-K-ion-coupled transport detected by streaming potential measurements.

PubMed: 31387976
DOI: 10.1073/pnas.1901888116

Experimental method

X-RAY DIFFRACTION (2.13 Å)