2A54:
reference: Structure and mechanism of the reversible photoswitch of a fluorescent protein., Andresen M, Wahl MC, Stiel AC, Grater F, Schafer LV, Trowitzsch S, Weber G, Eggeling C, Grubmuller H, Hell SW, Jakobs S, Proc Natl Acad Sci U S A 2005 Sep 13;102(37):13070-4. Epub 2005 Aug 31. PMID: 16135569

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