4ZSG:
reference: Discovery of a novel allosteric inhibitor-binding site in ERK5: comparison with the canonical kinase hinge ATP-binding site., Chen H, Tucker J, Wang X, Gavine PR, Phillips C, Augustin MA, Schreiner P, Steinbacher S, Preston M, Ogg D, Acta Crystallogr D Struct Biol. 2016 May 1;72(Pt 5):682-93. doi:, 10.1107/S2059798316004502. Epub 2016 Apr 26. PMID: 27139631

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