TY - JOUR
T1 - Control of KirBac3.1 potassium channel gating at the interface between cytoplasmic domains
AU - Zubcevic, Lejla
AU - Bavro, Vassiliy N.
AU - Muniz, Joao R.C.
AU - Schmidt, Matthias R.
AU - Wang, Shizhen
AU - De Zorzi, Rita
AU - Venien-Bryan, Catherine
AU - Sansom, Mark S.P.
AU - Nichols, Colin G.
AU - Tucker, Stephen J.
PY - 2014/1/3
Y1 - 2014/1/3
N2 - KirBac channels are prokaryotic homologs of mammalian inwardly rectifying potassium (Kir) channels, and recent structures of KirBac3.1 have provided important insights into the structural basis of gating in Kir channels. In this study, we demonstrate that KirBac3.1 channel activity is strongly pH-dependent, and we used x-ray crystallography to determine the structural changes that arise from an activatory mutation (S205L) located in the cytoplasmic domain (CTD). This mutation stabilizes a novel energetically favorable open conformation in which changes at the intersubunit interface in the CTD also alter the electrostatic potential of the inner cytoplasmic cavity. These results provide a structural explanation for the activatory effect of this mutation and provide a greater insight into the role of the CTD in Kir channel gating.
AB - KirBac channels are prokaryotic homologs of mammalian inwardly rectifying potassium (Kir) channels, and recent structures of KirBac3.1 have provided important insights into the structural basis of gating in Kir channels. In this study, we demonstrate that KirBac3.1 channel activity is strongly pH-dependent, and we used x-ray crystallography to determine the structural changes that arise from an activatory mutation (S205L) located in the cytoplasmic domain (CTD). This mutation stabilizes a novel energetically favorable open conformation in which changes at the intersubunit interface in the CTD also alter the electrostatic potential of the inner cytoplasmic cavity. These results provide a structural explanation for the activatory effect of this mutation and provide a greater insight into the role of the CTD in Kir channel gating.
UR - http://www.scopus.com/inward/record.url?scp=84891674459&partnerID=8YFLogxK
U2 - 10.1074/jbc.M113.501833
DO - 10.1074/jbc.M113.501833
M3 - Article
C2 - 24257749
AN - SCOPUS:84891674459
SN - 0021-9258
VL - 289
SP - 143
EP - 151
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 1
ER -