Although the crystal structures of α- and γ-coronavirus S1-NTDs are not available, they may also have the galectin fold for the following reason:
- The conserved structural topology of S1-CTDs across different coronavirus genera strongly suggests a similarly conserved structural topology of S1-NTDs across different coronavirus genera
- The S1-NTDs of both α-genus TGEV and γ-genus IBV function as lectins, although the former recognizes both N-glycolylneuraminic acid (Neu5Gc) and N-acetylneuraminic acid (Neu5Ac) and the latter recognizes Neu5Gc