6FK6:
reference: Ligand channel in pharmacologically stabilized rhodopsin., Mattle D, Kuhn B, Aebi J, Bedoucha M, Kekilli D, Grozinger N, Alker A, Rudolph MG, Schmid G, Schertler GFX, Hennig M, Standfuss J, Dawson RJP, Proc Natl Acad Sci U S A. 2018 Mar 19. pii: 1718084115. doi:, 10.1073/pnas.1718084115. PMID: 29555765

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