2X72:
reference: The structural basis of agonist-induced activation in constitutively active rhodopsin., Standfuss J, Edwards PC, D'Antona A, Fransen M, Xie G, Oprian DD, Schertler GF, Nature. 2011 Mar 31;471(7340):656-60. Epub 2011 Mar 9. PMID: 21389983

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