Structural insights into GORK channel gating

Xue Zhang 1, William Carroll 2, Thu B.A. Nguyen 2, Michael R. Blatt 2, Peng Zhang 1
1 Centre for Excellence in Molecular Plant sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
2 University of Glasgow, Glasgow, G12 8QQ, UK

The guard cell outward-rectifier potassium channel GORK is a member of the CNBD channel family and is the dominant pathway mediating K+ efflux for stomatal closure. Its bioengineering has demonstrated the potential for enhanced carbon assimilation and water use efficiencies. In this study, we determined the cryo-EM structure of Arabidopsis GORK in different states. The states are associated with interactions near the cytosolic face of the membrane between so-called voltage-sensor, C-linker and CNBHD domains, the latter positioned below the voltage sensor in the cytosol. These findings highlight intra- and inter-subunit interactions important for channel gating that are promising sites for optimizing GORK to engineer stomata.