TY - JOUR
T1 - Structural dynamics of potassium-channel gating revealed by single-molecule FRET
AU - Wang, Shizhen
AU - Vafabakhsh, Reza
AU - Borschel, William F.
AU - Ha, Taekjip
AU - Nichols, Colin G.
N1 - Funding Information:
Financial support was provided by US National Institutes of Health (NIH) grant HL54171 (C.G.N.) and US National Science Foundation grant PHY1430124 (T.H.). T.H. is supported as an investigator of the Howard Hughes Medical Institute. W.F.B. was supported by NIH grants T32 HL007275 and T32 HL125241.
Publisher Copyright:
© 2016 Nature America, Inc.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Crystallography has provided invaluable insights regarding ion-channel selectivity and gating, but to advance understanding to a new level, dynamic views of channel structures within membranes are essential. We labeled tetrameric KirBac1.1 potassium channels with single donor and acceptor fluorophores at different sites and then examined structural dynamics within lipid membranes by single-molecule fluorescence resonance energy transfer (FRET). We found that the extracellular region is structurally rigid in both closed and open states, whereas the N-terminal slide helix undergoes marked conformational fluctuations. The cytoplasmic C-terminal domain fluctuates between two major structural states, both of which become less dynamic and move away from the pore axis and away from the membrane in closed channels. Our results reveal mobile and rigid conformations of functionally relevant KirBac1.1 channel motifs, implying similar dynamics for similar motifs in eukaryotic Kir channels and in cation channels in general.
AB - Crystallography has provided invaluable insights regarding ion-channel selectivity and gating, but to advance understanding to a new level, dynamic views of channel structures within membranes are essential. We labeled tetrameric KirBac1.1 potassium channels with single donor and acceptor fluorophores at different sites and then examined structural dynamics within lipid membranes by single-molecule fluorescence resonance energy transfer (FRET). We found that the extracellular region is structurally rigid in both closed and open states, whereas the N-terminal slide helix undergoes marked conformational fluctuations. The cytoplasmic C-terminal domain fluctuates between two major structural states, both of which become less dynamic and move away from the pore axis and away from the membrane in closed channels. Our results reveal mobile and rigid conformations of functionally relevant KirBac1.1 channel motifs, implying similar dynamics for similar motifs in eukaryotic Kir channels and in cation channels in general.
UR - http://www.scopus.com/inward/record.url?scp=84954367060&partnerID=8YFLogxK
U2 - 10.1038/nsmb.3138
DO - 10.1038/nsmb.3138
M3 - Article
C2 - 26641713
AN - SCOPUS:84954367060
VL - 23
SP - 31
EP - 36
JO - Nature Structural and Molecular Biology
JF - Nature Structural and Molecular Biology
SN - 1545-9993
IS - 1
ER -