Structural similarity between HIV-1 gp41 and SARS-CoV S2 proteins suggests an analogous membrane fusion mechanism

SARS-associated coronavirus (SARS-CoV) has been identified as the causal agent of a new emerging disease: severe acute respiratory syndrome (SARS). Its spike protein S2 is responsible for mediating fusion of viral and cellular membrane. In this study, we modeled the 3D structure of S2 subunit and compared this model with the core structure of gp41 from HIV-1. We found that SARS-CoV S2 and gp41 share the same two α helices, suggesting that the two viruses could follow an analogous membrane fusion mechanism. Further ligand-binding analysis showed that two inhibitors GGL and D-peptide from HIV-1 gp41 may serve as inhibitors for SARS-CoV entry.