The ACE2 receptor accelerates but is not biochemically required for SARS-CoV-2 membrane fusion.

The SARS-CoV-2 coronavirus infects human cells the ACE2 receptor. Structural evidence suggests that ACE2 may not just serve as an attachment factor but also conformationally activate the SARS-CoV-2 spike protein for membrane fusion. Here, we test that hypothesis directly, using DNA-lipid tethering as a synthetic attachment factor in place of ACE2.