3FYR:
reference: Structure of the sporulation histidine kinase inhibitor Sda from Bacillus subtilis and insights into its solution state., Jacques DA, Streamer M, Rowland SL, King GF, Guss JM, Trewhella J, Langley DB, Acta Crystallogr D Biol Crystallogr. 2009 Jun;65(Pt 6):574-81. Epub 2009, May 15. PMID: 19465772

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