6GYH:
reference: Design of a light-gated proton channel based on the crystal structure of Coccomyxa rhodopsin., Fudim R, Szczepek M, Vierock J, Vogt A, Schmidt A, Kleinau G, Fischer P, Bartl F, Scheerer P, Hegemann P, Sci Signal. 2019 Mar 19;12(573). pii: 12/573/eaav4203. doi:, 10.1126/scisignal.aav4203. PMID: 30890657

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