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 pa thogenic Neisseria species. We isolated a glutathione peroxidase-relat ed 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 whic h is conserved among various species. The gpxA sequence was present in all 7 meningococcal strains tested but absent in 10 gonococcal strain s and 6 nonpathogenic neisserial strains as determined by Southern hyb ridization. The homology of gpxA to mammalian glutathione peroxidases and the presence of this gene specifically in the meningococcus sugges t that it is important in the cellular metabolism or defense processes particular to this pathogen.