Coronaviruses have evolved a complex receptor recognition pattern:
- coronaviruses use one or both S1 domains as RBDs
- highly similarly coronavirus S1-CTDs within the same genus can recognize different protein receptors, whereas very different coronavirus S1-CTDs from different genera can recognize the same protein receptor
- coronavirus S1-NTDs can recognize either protein or sugar receptors
Understanding the receptor recognition mechanisms of coronaviruses can provide critical insight into the origin, evolution, and receptor selection of coronaviruses.