title: Synechocystis Fe superoxide dismutase gene confers oxidative stress tolerance to Escherichia coli.
abstract: The superoxide dismutase (SOD) gene (slr 1516) from the cyanobacterium Synechocystis sp. PCC 6803 was cloned and overexpressed in Escherichia coli BL 21 (DE3) using the pET-20b(+) expression vector. E. coli cells transformed with pET-SOD overexpressed the protein in cytosol, upon induction by isopropyl beta-D-thiogalactopyranoside (IPTG). The recombinant protein was purified to near homogeneity by gel filtration and ion-exchange chromatography. The SOD activity of the recombinant protein was sensitive to hydrogen peroxide and sodium azide, confirming it to be FeSOD. The pET-FeSOD transformed E. coli showed significantly higher SOD activity and tolerance to paraquat-mediated growth inhibition compared to the empty vector transformed cells. Based on these results it is suggested that overexpression of FeSOD gene from a heterologous source like Synechocystis sp. PCC 6803 may provide protection to E. coli against superoxide radical-mediated oxidative stress mediated by paraquat.
authors.affiliation: Plant Molecular and Cellular Genetics, Bose Institute (Centenary Building), P-1/12, CIT Scheme VII M, Kolkata 700 054, India.
authors.forename: Jyotirmoy
authors.initials: J
authors.lastname: Bhattacharya
authors.forename: Krishnarup
authors.initials: K
authors.lastname: GhoshDastidar
authors.forename: Anirban
authors.initials: A
authors.lastname: Chatterjee
authors.forename: Manoj
authors.initials: M
authors.lastname: Majee
authors.forename: Arun Lahiri
authors.initials: AL
authors.lastname: Majumder
mesh_terms: D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000201:enzymology*; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D005798:Genes, Bacterial; D018384:Oxidative Stress; D010269:Paraquat / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D013482:Superoxide Dismutase; D010269:Paraquat