6GRM:
reference: Insight into GFPmut2 pH Dependence by Single Crystal Microspectrophotometry and X-ray Crystallography., Lolli G, Raboni S, Pasqualetto E, Benoni R, Campanini B, Ronda L, Mozzarelli A, Bettati S, Battistutta R, J Phys Chem B. 2018 Sep 17. doi: 10.1021/acs.jpcb.8b07260. PMID: 30179482

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