2OUA:
reference: Structural and mechanistic exploration of acid resistance: kinetic stability facilitates evolution of extremophilic behavior., Kelch BA, Eagen KP, Erciyas FP, Humphris EL, Thomason AR, Mitsuiki S, Agard DA, J Mol Biol. 2007 May 4;368(3):870-83. Epub 2007 Feb 22. PMID: 17382344

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