title: Characterization of the first angiotensin-converting like enzyme in bacteria: Ancestor ACE is already active.
abstract: Angiotensin-converting enzyme (ACE) is a metallopeptidase that converts angiotensin I into angiotensin II. ACE is crucial in the control of cardiovascular and renal homeostasis and fertility in mammals. In vertebrates, both transmembrane and soluble ACE, containing one or two active sites, have been characterized. So far, only soluble, single domain ACEs from invertebrates have been cloned, and these have been implicated in reproduction in insects. Furthermore, an ACE-related carboxypeptidase was recently characterized in Leishmania, a unicellular eukaryote, suggesting the existence of ACE in more distant organisms. Interestingly, in silico databank analysis revealed that bacterial DNA sequences could encode putative ACE-like proteins, strikingly similar to vertebrates' enzymes. To gain more insight into the bacterial enzymes, we cloned the putative ACE from the phytopathogenic bacterium, Xanthomonas axonopodis pv. citri, named XcACE. The 2 kb open reading frame encodes a 672-amino-acid soluble protein containing a single active site. In vitro expression and biochemical characterization revealed that XcACE is a functional 72 kDa dipeptidyl-carboxypeptidase. As in mammals, this metalloprotease hydrolyses angiotensin I into angiotensin II. XcACE is sensitive to ACE inhibitors and chloride ions concentration. Variations in the active site residues, highlighted by structural modelling, can account for the different substrate selectivity and inhibition profile compared to human ACE. XcACE characterization demonstrates that ACE is an ancestral enzyme, provoking questions about its appearance and structure/activity specialisation during the course of evolution.
authors.affiliation: Unité Neurosciences et Physiologie Adaptative, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cédex, France. guillaume.riviere@dkf.unibe.ch
authors.forename: Guillaume
authors.initials: G
authors.lastname: Rivière
authors.forename: Annie
authors.initials: A
authors.lastname: Michaud
authors.forename: Hazel R
authors.initials: HR
authors.lastname: Corradi
authors.forename: Edward D
authors.initials: ED
authors.lastname: Sturrock
authors.forename: K
authors.initials: K
authors.lastname: Ravi Acharya
authors.forename: Virginie
authors.initials: V
authors.lastname: Cogez
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bohin
authors.forename: Didier
authors.initials: D
authors.lastname: Vieau
authors.forename: Pierre
authors.initials: P
authors.lastname: Corvol
mesh_terms: D000595:Amino Acid Sequence; D000803:Angiotensin I / Q000737:chemistry; D000804:Angiotensin II / Q000737:chemistry; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D003001:Cloning, Molecular; D019295:Computational Biology; D016680:Genome, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D010802:Phylogeny; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D053532:Xanthomonas axonopodis / Q000201:enzymology* / Q000235:genetics
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D001426:Bacterial Proteins; D000804:Angiotensin II; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A