S1-NTDs of β-genus coronaviruses

β-genus MHV S1-NTD complexed with mouse CEACAM1 was the first structure available for a coronavirus S1-NTD and S1-NTD/receptor complex. Surprisingly, MHV S1-NTD contains a core structure that has the same structural fold as human galectins (galactose-binding lectins). The core structure of  MHV S1-NTD is thirteen-stranded β-sandwich consisting of two sheet β-sheet layers of six and seven strands, respectively.