Occurrence of two superoxide dismutases in Aeromonas hydrophila: molecular cloning and differential expression of the sodA and sodB genes

• Published in: Microbiology (Society for General Microbiology) 2001-11, Vol.147 (11), p.3105-3111
• Main Authors: Leclere, Valerie, Chotteau-Lelievre, Anne, Gancel, Frederique, Imbert, Marlene, Blondeau, Roland
• Format: Article
• Language: English
• Subjects: Aeromonas - enzymology; Aeromonas - genetics; Aeromonas hydrophila; Bacterial Proteins - genetics; Bacterial Proteins - isolation & purification; Bacterial Proteins - metabolism; Bacteriology; Biological and medical sciences; Cloning, Molecular; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial - drug effects; Gene Expression Regulation, Enzymologic - drug effects; Genetics; Iron - metabolism; Isoenzymes - genetics; Microbiology; Molecular Sequence Data; Paraquat - pharmacology; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; sodA gene; sodB gene; Superoxide Dismutase - genetics; Superoxide Dismutase - isolation & purification; Superoxide Dismutase - metabolism
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-147-11-3105

Laboratoire de Microbiologie 1 and Laboratoire de Biologie du Développement 2 , Université des Sciences et Technologies de Lille, F-59655 Villeneuve d’Ascq Cedex, France Author for correspondence: Valérie Leclère. Tel: [phone]. Fax: [phone]. e-mail: Valerie.Leclere{at}univ-lille1.fr Aeromonas spp ., considered as emerging opportunistic pathogens, belong to the family Vibrionaceae . Among the criteria currently used for their classification is the presence of a single FeSOD (iron-containing superoxide dismutase), which distinguishes them from Enterobacteriaceae . In this paper the cloning of the sodA and sodB genes encoding two different SODs in Aeromonas hydrophila ATCC 7966 is reported. The sodB gene encoded an FeSOD (196 amino acids, 21·5 kDa), was constitutively expressed and showed 75% homology with the E. coli FeSOD. The sodA gene encoded a protein of 206 amino acids (22·5 kDa) with MnSOD (manganese-containing SOD) activity and showed 55% homology with the Escherichia coli MnSOD. The MnSOD of A. hydrophila was detected only during the stationary phase of growth under high aeration or when induced by lack of iron. Nevertheless, paraquat had no detectable effect on its production. The amino-terminal part of the Mn-containing protein contained a putative signal sequence which could permit a periplasmic localization. Keywords: Vibrionaceae , MnSOD, FeSOD Abbreviations: CDM, chemically defined medium; DIP, 2,2'-dipyridyl; EDDA, ethylenediamine di-( o -hydroxyphenylacetic acid); PQ, paraquat; SOD, superoxide dismutase The GenBank accession numbers for the sequences reported in this paper are AF317226 and AF317227 .