Fig. 3

Sequence and aa residues of ACE2. A ACE2 gene encoding a deduced 805-aa protein. The unprocessed ACE2 (1–17) and ACE2 chain (18–805). Functional roles are illustrated based on [34] and [35]. (https://www.uniprot.org/uniprot/Q9BYF1/protvista). B ACE2 sequence contains an N-terminal signal (1 to 18), a TM domain (740 to 763), and a metalloprotease zinc-binding consensus (374 to 378, HEMGH). Blue aa residues are required for RBD interaction with the extracellular catalytic domain of ACE2 [36]. C. 3D structure of the ACE2 protein (https://www.uniprot.org/uniprot/Q9BYF1/protvista)