5D9H:
reference: Domain-Swapping Switch Point in Ste20 Protein Kinase SPAK., Taylor CA 4th, Juang YC, Earnest S, Sengupta S, Goldsmith EJ, Cobb MH, Biochemistry. 2015 Aug 18;54(32):5063-71. doi: 10.1021/acs.biochem.5b00593. Epub , 2015 Aug 3. PMID: 26208601

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