Fig. 4

Molecular structures of CusD_I and CusD_II. a Overlay of ribbon representations of CusD_I (blue), CusD_II (green) with B. ovatus SusD homologue SGBP-A (gray, PDB 5E76). Xyloglucooligosaccharide (XyGO₂) bound to SGBP-A is shown in yellow and red sticks. b Surface-accessible residues of CusD_I (blue) and CusD_II (green) within 5 Å of the XyGO₂ from the superposition with SGBP-A are displayed. c and d Space-fill models of CusD_I and CusD_II, respectively, with surface-accessible residues, as in b, in black, illustrating the different binding surfaces of the two proteins. Surface accessibility was calculated using CCP4 (40)