Extended Data Figure 2.

(a) Zoom-in view at the Int-D binding site demonstrating hydrophobic interactions between ZNF831 peptide (shown as sticks) and Int-D in OGT_4.5 (shown as surface). Red and white colors represent the least and most hydrophobic areas, respectively. (b) Zoom-in view at the Int-D binding site demonstrating polar interactions between ZNF831 peptide (shown as purple sticks) and Int-D in OGT_4.5 (shown as surface) with interacting OGT residues shown in sticks. 2F_o–F_c electron density map of ZNF831 peptide is shown as grey mesh and contoured at 1.0 σ, F_o–F_c electron density map is shown as green mesh and contoured at 3.0 σ. (c) Zoom-in view at the Int-D binding site demonstrating hydrophobic interactions between CP37 peptide (shown as sticks) and Int-D in OGT_4.5 (shown as surface). Red and white colors represent the least and most hydrophobic areas, respectively. (d) Zoom-in view at the Int-D binding site demonstrating polar interactions between CP37 peptide (shown as blue sticks) and Int-D in OGT_4.5 (shown as surface) with interacting OGT residues shown in sticks. 2F_o–F_c electron density map of CP37 peptide is shown as grey mesh and contoured at 1.0 σ, F_o–F_c electron density map is shown as green mesh and contoured at 3.0 σ. (e) Superimposition of OGT_4.5:UDP-GlcNAc (4GZ5, grey), OGT_4.5:UDP-GlcNAc:SMG9 (magenta), OGT_4.5:UDP-GlcNAc:ZNF831 (purple), and OGT_4.5:UDP-GlcNAc:CP37 (blue) crystal structures showing peptide binding to Int-D does not change the overall structure of OGT_4.5. (f) A proposed model of a substrate peptide (shown as brown cartoon) binding to OGT_4.5 (shown as surface, domains colored as in Figure 1a). Int-D and TPR domain interactions facilitate substate glycosylation in the active site of OGT. G symbol represents GlcNAc moiety.