Extended Data Fig. 5. Potential extracellular facing odour-binding pocket.

a, Side view of Orco highlighting the location of residues in ORs that, when mutated, alter ligand binding specificity. Orco residues that are equivalent to point mutations that alter odour specificity in Helicoverpa assaulta OR14b²⁴, An. gambiae OR15²⁵, D. melanogaster OR85b²⁶ or Ostrinia furnacalis OR3²⁷ are shown as red spheres. Residues required for VUAA1 sensitivity in Orco²³ are shown as blue spheres. In Orco, the S3–S4 extracellular loop is positioned above the pocket. b, A 15-Å cross-section through the pocket from a.