Fig. 4: Structures of SgUGT94-289-3 in complex with sugar acceptors in pocket 2.
a Cartoon representation of M3 structure. Two M3 molecules are shown in stick-ball mode, and one of the two M3 molecules binds in pocket 2 and is further shown in surface mode, with its 6-OH (O6) of R2-G1 indicated by a red arrow. UDP and the catalytic residue H22 are shown as sticks. b Structure alignment of M3 and SIAV148G. NTD and CTD of M3 structure are shown in marine and magenta. SIAV148G structure is shown in gray. Substrates bound in M3 and SIAV148G structures are shown in purple and orange, respectively. c Superposition of M3 structure and the structure of OsUGT91C1 complexed with UDP and Reb E (PDB code 7ES0). Proteins are shown in cartoon mode, UDP, sugar acceptors and H22 are shown as sticks. Molecules M3 (green stick) and Reb E (white stick), including their oxygen atoms waiting to be glucosylated (colored red and indicated by arrows), are superposed well in pocket 2. d Binding of M3 molecule in pocket 2 and its interactions with SgUGT94-289-3. M3, UDP and adjacent residues are shown as stick-ball, stick and lines, respectively. Hydrogen-bond interactions are shown by black dashed lines. Hydrophobic residues are shown as dots.
