Synechocystis Fe superoxide dismutase gene confers oxidative stress tolerance to Escherichia coli.
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.
Bhattacharya
Jyotirmoy
J
Plant Molecular and Cellular Genetics, Bose Institute (Centenary Building), P-1/12, CIT Scheme VII M, Kolkata 700 054, India.
GhoshDastidar
Krishnarup
K
Chatterjee
Anirban
A
Majee
Manoj
M
Majumder
Arun Lahiri
AL
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*
D011994:Recombinant Proteins; D013482:Superoxide Dismutase; D010269:Paraquat