Fig. 3

The 3D-structure models of CrCBM13. a The structure alignment of SlCBM13-Xylopentaose complex (PDB ID: 1MC9) and CrCBM13. The SlCBM13-Xylopentaose complex and CrCBM13 are colored as dark green and sky blue, respectively. The side chains of the amino acid residues involved in binding xylopentaose in SlCBM13 and of the amino acid residues at the same sequence sites in CrCBM13 are displayed. The pink spheres represent water molecules and the gray dashed lines represent hydrogen bonds. b The CrCBM13-Araf-X3 complex based on protein-small molecule docking. Yellow and blue areas represent hydrophobic and hydrophilic surfaces, respectively. c The amino acid residues involved in binding Araf-X3 of CrCBM13. The green dashed lines represent hydrogen bonds. d Sequence alignment of CBM13. The amino acid residues involved in binding Araf-X3 in CrCBM13 are indicated by red arrows, and the GNG β-sheet is marked with a square. Protein structures of the other three CBMs are accessible at PDB database (1V6V, 1MC9, 3VSZ) [22, 25, 52]