4A1G:
reference: Structural analysis reveals features of the spindle checkpoint kinase Bub1-kinetochore subunit Knl1 interaction., Krenn V, Wehenkel A, Li X, Santaguida S, Musacchio A, J Cell Biol. 2012 Feb 20;196(4):451-67. Epub 2012 Feb 13. PMID: 22331848

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