title: A unique enzyme of acetic acid bacteria, PQQ-dependent alcohol dehydrogenase, is also present in Frateuria aurantia.
abstract: A membrane-bound, pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) was purified from Frateuria aurantia LMG 1558(T). Although F. aurantia belongs to a group of γ-Proteobacteria, the characteristics of its PQQ-ADH were similar to the enzyme characteristics of the typical high-acetic acid-resistant bacterium Gluconacetobacter europaeus from the group of α-Proteobacteria. The PQQ-dependent ADH was solubilized from the membranes and purified after anionic, cationic, and affinity chromatography with specific activity of 117 U/mg. The purified enzyme was estimated to be composed of two subunits of ca. 72 and 45 kDa, as judged by SDS-polyacrylamide gel electrophoresis. The purified enzyme had maximum activity at pH 4.5 and showed the highest substrate specificity to ethanol, isoamyl alcohol, 1-butanol, and 1-propanol. The deduced sequences of cloned genes adhA and adhB encoding subunits I and II of PQQ-ADH showed 80 % amino acid (AA) identity to AdhA and 68 % AA identity to AdhB of Ga. europaeus V3 (LMG 18494). Because of the high similarity between genes encoding subunits I and II of PQQ-ADH and its homologous genes found in a distantly related taxonomic group of acetic acid bacteria, the results suggest the possibility of horizontal gene transfer between these two groups of genera.
authors.affiliation: Faculty of Natural Sciences and Mathematics, Department of Biology, University of Maribor, Maribor, Slovenia. janja.trcek@uni-mb.si
authors.forename: Janja
authors.initials: J
authors.lastname: Trček
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Matsushita
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D041821:Gluconacetobacter / Q000201:enzymology / Q000235:genetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D055503:Protein Multimerization; D021122:Protein Subunits; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D044166:Xanthomonadaceae / Q000201:enzymology* / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D021122:Protein Subunits; D000429:Alcohol Oxidoreductases; C048312:polyvinyl-alcohol dehydrogenase (acceptor)