2P4M:
reference: A structural basis for the pH-dependent increase in fluorescence efficiency of chromoproteins., Battad JM, Wilmann PG, Olsen S, Byres E, Smith SC, Dove SG, Turcic KN, Devenish RJ, Rossjohn J, Prescott M, J Mol Biol. 2007 May 11;368(4):998-1010. Epub 2007 Feb 9. PMID: 17376484

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