title: Expression and characterization of an iron-containing superoxide dismutase from Burkholderia pseudomallei.
abstract: A superoxide dismutase (SOD) gene from Burkholderia pseudomallei, the causative agent of melioidosis, was cloned and expressed in Escherichia coli, and its product was functionally and physically characterized. The gene has an open-reading frame of 579 bp. The deduced amino acid sequence has 192 residues with a calculated molecular mass of ~22 kDa. Sequence comparison with other bacterial SODs showed that the protein contains typical metal-binding motifs and other Fe-SOD-conserved residues. The sequence has substantial similarity with other bacterial Fe-SOD sequences. The enzymatic activity of the expressed protein was inhibited by hydrogen peroxide but not by sodium azide or potassium cyanide, attributes that indeed are characteristic of typical bacterial Fe-SODs. Western blotting with antiserum against the recombinant Fe-SOD revealed that it is expressed in B. pseudomallei. Transformed E. coli that expressed the Fe-SOD had significantly increased SOD activity and was highly tolerant to paraquat-mediated replication inhibition, compared to transformed cells carrying an empty vector. Our results provide a basis for further biochemical characterization of the enzyme and elucidation of its role in the pathogenesis of B. pseudomallei.
authors.affiliation: Division of High-Risk Pathogen Research, Center for Infectious Diseases, National Institute of Health, Chungbuk 363-951, Republic of Korea.
authors.forename: Min-Hee
authors.initials: MH
authors.lastname: Cho
authors.forename: Yong-Woo
authors.initials: YW
authors.lastname: Shin
authors.forename: Jeong-Hoon
authors.initials: JH
authors.lastname: Chun
authors.forename: Kee-Jong
authors.initials: KJ
authors.lastname: Hong
authors.forename: Byoung-Kuk
authors.initials: BK
authors.lastname: Na
authors.forename: Gi-Eun
authors.initials: GE
authors.lastname: Rhie
authors.forename: Baik-Lin
authors.initials: BL
authors.lastname: Seong
authors.forename: Cheon-Kwon
authors.initials: CK
authors.lastname: Yoo
mesh_terms: D000595:Amino Acid Sequence; D016957:Burkholderia pseudomallei / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D015870:Gene Expression; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013482:Superoxide Dismutase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D013482:Superoxide Dismutase