Recombinant ACE2 SARS-CoV2 Binding Domain

The sequence below is that of our recombinant construct of the ACE2 extracellular domain which includes the entire region which interacts with both SARS-CoV1 and SARS-CoV2. The specific binding of both SARS viruses to ACE2 is essential for viral internalization and infection. We designed this construct based on amino acids 1-500 in the S-protein sequence in BAB40370.1. This is a defined globular domain recently shown to include all of the amino acids necessary for ACE2 binding (4) . Human ACE2 is 805 amino acids long so this construct is missing the C-terminal 305 amino acids, which at 741-763, includes a membrane spanning domain. The construct lacks this region as inclusion would likely have made the molecule difficult to express. The construct was expressed in and purified from E. coli and includes an N-terminal His-tag and other vector derived sequence shown underlined below. Amino acids printed in bold below are those which have been shown to interact with the SARS-CoV2 binding domain.