6RF3:
reference: Structure and mechanisms of sodium-pumping KR2 rhodopsin., Kovalev K, Polovinkin V, Gushchin I, Alekseev A, Shevchenko V, Borshchevskiy V, Astashkin R, Balandin T, Bratanov D, Vaganova S, Popov A, Chupin V, Buldt G, Bamberg E, Gordeliy V, Sci Adv. 2019 Apr 10;5(4):eaav2671. doi: 10.1126/sciadv.aav2671. eCollection 2019, Apr. PMID: 30989112

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