Four superoxide dismutase (isozymes) genes of Bacillus cereus

Abstract

Bacillus cereus is a ubiquitous soil bacterium which requires the enzyme superoxide dismutase (SOD) to protect it from toxic reactive oxygen species. In this study, two new SOD genes, encoding CuZnSOD and FeSOD, have been isolated from B. cereus 905. Critical residues commonly used to predict specificity in CuZnSOD or FeSOD are observed in the putative peptides. The two new SODs along with documented genes that encode two MnSODs showed SOD activities upon expression in Escherichia coli. Amino acid sequence analysis revealed that the SODs had significant homology with the B. cereus group. Bacillus cereus seems to use a unique mechanism to utilize these four SODs for its protection. © Springer-Verlag and the University of Milan 2010.