1R4L | pdb_00001r4l

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ACE2 X-ray structures reveal a large hinge-bending motion important for inhibitor binding and catalysis.

(2004) J Biological Chem 279: 17996-18007

• PubMed: 14754895 Search on PubMedSearch on PubMed Central
• DOI: https://doi.org/10.1074/jbc.M311191200
• Primary Citation Related Structures: 
  1R42, 1R4L


• PubMed Abstract: 
  

  The angiotensin-converting enzyme (ACE)-related carboxypeptidase, ACE2, is a type I integral membrane protein of 805 amino acids that contains one HEXXH + E zinc-binding consensus sequence. ACE2 has been implicated in the regulation of heart function and also as a functional receptor for the coronavirus that causes the severe acute respiratory syndrome (SARS). To gain further insights into this enzyme, the first crystal structures of the native and inhibitor-bound forms of the ACE2 extracellular domains were solved to 2.2- and 3.0-A resolution, respectively. Comparison of these structures revealed a large inhibitor-dependent hinge-bending movement of one catalytic subdomain relative to the other ( approximately 16 degrees ) that brings important residues into position for catalysis. The potent inhibitor MLN-4760 ((S,S)-2-[1-carboxy-2-[3-(3,5-dichlorobenzyl)-3H-imidazol4-yl]-ethylamino]-4-methylpentanoic acid) makes key binding interactions within the active site and offers insights regarding the action of residues involved in catalysis and substrate specificity. A few active site residue substitutions in ACE2 relative to ACE appear to eliminate the S(2)' substrate-binding subsite and account for the observed reactivity change from the peptidyl dipeptidase activity of ACE to the carboxypeptidase activity of ACE2.

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Organizational Affiliation: 
• Drug Discovery and Protein Sciences, Millennium Pharmaceuticals, Incorporated, Cambridge, Massachusetts 02139, USA.