Detection and characterisation of the genes encoding glyoxalase I and II from Neisseria meningitidis

Glyoxalase enzymes I and II are involved in a detoxification process consis ting of conversion of reactive dicarbonyl compounds (e.g., methylglyogal) t o less reactive hydroxy acids. The structural gene for meningococcal glyoxa lase I(gloA) was identified by screening an expression library with a rabbi t antiserum. The meningococcal gloA gene consisted of 138 deduced amino aci ds, with a calculated mel. wt of 15.7 kDa, The DNA and deduced protein sequ ence of gloA was compared to known sequences of glyoxalase I enzymes and sh owed high homology with gloA of several eukaryotic and prokaryotic species. Insertion of a gloA-containing plasmid in Escherichia coli increased the h ost organism's tolerance to methylglyoxal from <2 mM to >4 mM, thus demonst rating its functional identity: A databank search also revealed the presenc e of a putative gloB gene, encoding glyoxalase II (GlxII), in the recently released genomic sequences of Neisseria meningitidis and N. gonorrhoeae.