Essential counter-regulatory carboxypeptidase of the renin-angiotensin hormone system that is a critical regulator of blood volume, systemic vascular resistance, and thus cardiovascular homeostasis. Converts angiotensin I to angiotensin 1-9, a nine-amino acid peptide with anti-hypertrophic effects in cardiomyocytes, and angiotensin II to angiotensin 1-7, which then acts as a beneficial vasodilator and anti-proliferation agent, counterbalancing the actions of the vasoconstrictor angiotensin II. Also removes the C-terminal residue from three other vasoactive peptides, neurotensin, kinetensin, and des-Arg bradykinin, but is not active on bradykinin. Also cleaves other biological peptides, such as apelins, casomorphins and dynorphin A. Plays an important role in amino acid transport by acting as binding partner of amino acid transporter SLC6A19 in intestine, regulating trafficking, expression on the cell surface, and its catalytic activity. (Microbial infection) Acts as a receptor for human coronavirus SARS. angiotensin II + H2O = angiotensin-(1-7) + L-phenylalanine angiotensin I + H2O = angiotensin-(1-9) + L-leucine Binds 1 zinc ion per subunit. Binds 1 Cl(-) ion per subunit. Homodimer. Interacts with the catalytically active form of TMPRSS2 (By similarity). Interacts with SLC6A19; this interaction is essential for expression and function of SLC6A19 in intestine (By similarity). Interacts with ITGA5:ITGB1 (By similarity). Probably interacts (via endocytic sorting signal motif) with AP2M1; the interaction is inhibited by phosphorylation of Tyr-781 (By similarity). Interacts (via PDZ-binding motif) with SLC9A3R1 (via PDZ domains); the interaction may enhance ACE2 membrane residence (By similarity). (Microbial infection) Interacts with SARS-CoV S protein. Detected in both cell membrane and cytoplasm in neurons. The cytoplasmic tail contains several linear motifs such as LIR, PDZ-binding, PTB and endocytic sorting signal motifs that would allow interaction with proteins that mediate endocytic trafficking and autophagy. Proteolytic cleavage by ADAM17 generates a secreted form. Also cleaved by serine proteases: TMPRSS2, TMPRSS11D and HPN/TMPRSS1 (By similarity). Phosphorylated. Phosphorylation at Tyr-781 probably inhibits interaction with AP2M1 and enables interactions with proteins containing SH2 domains. Belongs to the peptidase M2 family.