Distinct gating mechanisms revealed by the structures of a multi-ligand gated K+ channel

eLife

Sheng Ye¹  Yeeling Lam¹  Chunguang Kong²  Mehabaw Getahun Derebe²  Youxing Jiang²  Weizhong Zeng²  David Bryant Sauer²  Liping Chen³ 

[1] Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States;Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States;Life Sciences Institute, Zhejiang University, Hangzhou, China;

关键词: Geobacter sulfurreducens;    K+ channel;    ligand gating;   

DOI  :  10.7554/eLife.00184

来源: DOAJ

【 摘 要 】

The gating ring-forming RCK domain regulates channel gating in response to various cellular chemical stimuli in eukaryotic Slo channel families and the majority of ligand-gated prokaryotic K+ channels and transporters. Here we present structural and functional studies of a dual RCK-containing, multi-ligand gated K+ channel from Geobacter sulfurreducens, named GsuK. We demonstrate that ADP and NAD+ activate the GsuK channel, whereas Ca2+ serves as an allosteric inhibitor. Multiple crystal structures elucidate the structural basis of multi-ligand gating in GsuK, and also reveal a unique ion conduction pore with segmented inner helices. Structural comparison leads us to propose a novel pore opening mechanics that is distinct from other K+ channels.

【 授权许可】

Unknown