4ZKI:
reference: Conformational dynamics of the essential sensor histidine kinase WalK., Cai Y, Su M, Ahmad A, Hu X, Sang J, Kong L, Chen X, Wang C, Shuai J, Han A, Acta Crystallogr D Struct Biol. 2017 Oct 1;73(Pt 10):793-803. doi:, 10.1107/S2059798317013043. Epub 2017 Sep 27. PMID: 28994408

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