Amino acid sequence comparison of the S1 subunit (corresponding to aa 1–660 of the spike protein of SARS-CoV).

<p>The receptor-binding domain (aa 318–510) of SARS-CoV and the homologous region of bat SARSr-CoVs are indicated by the red box. The key aa residues involved in the interaction with human ACE2 are numbered on top of the aligned sequences. SARS-CoV GZ02, BJ01 and Tor2 were isolated from patients in the early, middle and late phase, respectively, of the SARS outbreak in 2003. SARS-CoV SZ3 was identified from civets in 2003. SARSr-CoV Rs 672 and YN2013 were identified from <i>R</i>. <i>sinicus</i> collected in Guizhou and Yunnan Province, respectively. SARSr-CoV Rf1 and JL2012 were identified from <i>R</i>. <i>ferrumequinum</i> collected in Hubei and Jilin Province, respectively. WIV1, WIV16, RsSHC014, Rs4081, Rs4084, Rs4231, Rs4237, Rs4247, Rs7327 and Rs4874 were identified from <i>R</i>.<i>sinicus</i>, and Rf4092 from <i>R</i>. <i>ferrumequinum</i> in the cave surveyed in this study.