Fig. 4: Cryo-EM structures of AuraA and two ternary complexes of AuraA (DMSPP-2 and DMSPP-3).

a Cartoon representation of AuraA (yellow, PDB ID 8Y9E), AuraA-DMSPP-2 (magenta, PDB ID 8Y9D), and AuraA-DMSPP-3 (cyan, PDB ID 8Y9G) viewed from the top. The salmon shadow highlights differences in the β1-β2 turn region (residues A₁₁₁GES₁₁₄) between the two holo-structures and the apo structure in the cartoon representation. The β1-β2 turn region (residues A₁₁₁GES₁₁₄) of AuraA (yellow), AuraA-DMSPP-2 (magenta), and AuraA-DMSPP-3 (cyan) is displayed in stick and surface (60% transparency) representation. b Key residues in the catalytic chamber of AuraA are categorized into three regions: the prenyl donor binding pocket (green), the tyrosine shield (purpleblue), and the acceptor binding pocket (gray80). c Structures of prenyl donors and acceptors, along with residues of tyrosine shields (purpleblue), from AuraA-Apo, AuraA-DMSPP-2 (magenta), and AuraA-DMSPP-3 (cyan), are shown in sticks. Residues Y207 and Y280 exhibit significantly different conformations in two ternary complexes, marked separately in salmon. Q337 (gray70) acts as a key residue for substrate binding, while the conformational change of Y280 creates space for its interaction with the substrate. The dashed line, colored with gray60, indicates a hydrogen bond interaction between two atoms.