Cryo-EM structure reveals a symmetry reduction of the plant outward-rectifier potassium channel SKOR
Siyu Li, Yuanxia Wang, Chenyang Wang, Yong Zhang, Demeng Sun, Peng Zhou, Changlin Tian, Sanling Liu
Abstract
In plant, the family of voltage-gated potassium channel is crucial for K + uptake, release, and distribution, playing important roles in plant growth and development 1 , 2 . Among these channels, the Stelar K + outward rectifier channel (SKOR) functions as a K + efflux channel for long-distance distribution of K + from roots to the upper parts of the plant 3 , 4 . There are only two structures of voltage-gated K + channels, KAT1 and AKT1 from Arabidopsis , reported to date 5 , 6 , 7 . Notably, KAT1/AKT1 and SKOR represent two different types of K + channels that share an extensively similar structural background but display profoundly different biophysical characteristics, belonging to K in and K out channels, respectively 2 . Interestingly, SKOR contains an intracellular ankyrin repeat (ANK) domain, which is absent in all the depolarization-activated K + channels with known structure. Here, we reported the cryo-EM structure of SKOR, and investigated the role of the ANK domain in channel structure and function modulation.