Isolation and identification of a glutathione peroxidase homolog gene, gpxA, present in Neisseria meningitidis but absent in Neisseria gonorrhoeae.

Antioxidant enzymes are thought to be important for the survival of pathogenic Neisseria species. We isolated a glutathione peroxidase-related gene (gpxA) from Neisseria meningitidis FAM20. The N. meningitidis glutathione peroxidase homolog was 49 to 57% identical to seven other glutathione peroxidase family members over a 49-amino-acid region which is conserved among various species. The gpxA sequence was present in all 7 meningococcal strains tested but absent in 10 gonococcal strains and 6 nonpathogenic neisserial strains as determined by Southern hybridization. The homology of gpxA to mammalian glutathione peroxidases and the presence of this gene specifically in the meningococcus suggest that it is important in the cellular metabolism or defense processes particular to this pathogen.