Fig. 2: Structural details of Spindlin1/C11orf84/H3K4me3K9me3 ternary complex.
a Cartoon representation of the structure of Spindlin1/C11orf84 bound to H3K4me3K9me3 peptide. Spindlin1 Tudor 1, Tudor 2, and Tudor 3 domains are colored in light pink, green, and cyan, respectively. The C11orf84 segment and H3K4me3K9me3 peptide are colored in orange and yellow, respectively. b Detailed view of the interaction between C11orf84 and Spindlin1 Tudor 3 domain. Key residues involved in the interaction are depicted as stick models and labeled. Hydrogen bonds and salt bridges are shown in magenta dashed lines. c Structural comparison with the previous determined Spindlin1/H3K4me3R8me2a binary complex (PDB: 4MZF, colored in light gray) revealed that binding of C11orf84 fragment induced conformational changes in Spindlin1 Tudor 3 domain. The red dash box highlights the Y256-K260 segment of Tudor 3 adopts a β-strand conformation upon C11orf84 binding. In addition, the Tudor 3 β1–loop–β2 region was pushed outward with ~6 Å in distance to accommodate the C11orf84 fragment. d The detailed interaction network of Spindlin1/C11orf84 with H3K4me3K9me3 peptide. The H3K4me3K9me3 segment is depicted as yellow sticks. Hydrogen bonds and salt bridges are shown in magenta dashes. e ITC fitting curves for binding of Spindlin1/C11orf84 complex including Spindlin1 wild type and mutants to the H3K4me3K9me3 peptide, along with the calculated Kd. The thermodynamic parameters are listed in Supplementary Table 3.
