title: New light on bacterial carbonic anhydrases phylogeny based on the analysis of signal peptide sequences.
abstract: Among protein families, carbonic anhydrases (CAs, EC 4.2.1.1) are metalloenzymes characterized by a common reaction mechanism in all life domains: the carbon dioxide hydration to bicarbonate and protons (CO2+H2O ⇔ HCO3(-)+H(+)). Six genetically distinct CA families are known to date, the α-, β-, γ-, δ-, ζ- and η-CAs. The last CA class was recently discovered analyzing the amino acid sequences of CAs from Plasmodia. Bacteria encode for enzymes belonging to the α-, β-, and γ-CA classes and recently, phylogenetic analysis revealed an interesting relationship regarding the evolution of bacterial CA classes. This result evidenced that the three bacterial CA classes, in spite of the high level of the structural similarity, are evolutionarily distinct, but we noted that the primary structure of some β-CAs identified in the genome of Gram-negative bacteria present a pre-sequence of 18 or more amino acid residues at the N-terminal part. These observations and subsequent phylogenetic data presented here prompted us to propose that the β-CAs found in Gram-negative bacteria with a periplasmic space and characterized by the presence of a signal peptide might have a periplasmic localization and a role similar to that described previously for the α-CAs.
authors.affiliation: a Dipartimento Neurofarba, Sezione di Scienze Farmaceutiche e Nutraceutiche and.|b Dipartimento di Chimica, Laboratorio di Chimica Bioinorganica, Polo Scientifico, Università degli Studi di Firenze , Sesto Fiorentino , Florence , Italy , and.
authors.forename: Claudiu T
authors.initials: CT
authors.lastname: Supuran
authors.affiliation: c Istituto di Bioscienze e Biorisorse, CNR , Napoli , Italy.
authors.forename: Clemente
authors.initials: C
authors.lastname: Capasso
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology*; D001483:Base Sequence; D002256:Carbonic Anhydrases / Q000145:classification*; D010802:Phylogeny; D021382:Protein Sorting Signals
chemical_list: D021382:Protein Sorting Signals; D002256:Carbonic Anhydrases
keywords: CA classes; carbonic anhydrases; cleavage site; metalloenzymes; phylogenetic analysis; protein evolution; signal peptide