4EEP:
reference: Structural Tuning of the Fluorescent Protein iLOV for Improved Photostability., Christie JM, Hitomi K, Arvai AS, Hartfield KA, Mettlen M, Pratt AJ, Tainer JA, Getzoff ED, J Biol Chem. 2012 May 9. PMID: 22573334

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