3.E.1.1.4
Archaerhodopsin 3, archaerhodopsin-3, AR3, Aop3, BACR3 of 258 aas and 7 TMSs.  It pumps protons in response to light absorption (Saint Clair et al. 2012) and is 86% identical to 3.E.1.1.2. Structures of the archaerhodopsin-3 transporter reveal that disordering of internal water networks underpins receptor sensitization (Bada Juarez et al. 2021). Opsin-based transmembrane voltage sensors (OTVSs) are membrane proteins increasingly used in optogenetic applications to measure voltage changes across cellular membranes (Mei et al. 2021).  Khangholi et al. 2021 studied photoactivation of cell-free expressed archaerhodopsin-3 in a model cell membrane and concluded that it functions as a channel with open and closed states and a pore radius of 0.3 nm.