Isolation, expression, and nucleotide sequence of the sod gene from Porphyromonas gingivalis

The sod gene coding for the Mn/Fe-dependent superoxide dismutase (SOD) enzyme has been isolated on a 5.9-kb DNA fragment from Porphyromonas gingivalis ATCC 53977. SOD activity can be expressed from the P. gingivalis fragment and from a subcloned fragment in Escherichia coli. However, the enzyme does not appear to be expressed from its own promoter in E. coli cells. The nucleotide sequence of the gene has been determined, and the deduced amino acid sequence of the enzyme is nearly identical to that of the enzyme purified from P. gingivalis 381 and shares extensive sequence similarity with comparable enzymes from E. coli.