The galE gene from Haemophilus influenzae was used as a hybridization probe for the galE gene of Neisseria meningitidis Group B, identifying two different homologous ioci. Each of the loci was cloned and nucleotide sequence analysis revealed that both loci contained sequences similar to galE. One contained a functional galEgene and mapped to the capsule biosynthetic locus. The second contained only a partial ga/E-coding sequence, which did not express a functional gene product. A galE mutant meningococcal strain was constructed by transformation with an inactivated galE gene. Analysis of the LPS from the ga/Emutant strain revealed an apparent reduction in moiecular weight and a loss of reactivity with monoclonal antibodies specific for structures known to contain galactose. These results are consistent with an essential role for galE in the incorporation of galactose into meningococcal lipopolysaccharide.

No abstract

The galE gene from Haemophilus influenzae was used as a hybridization probe for the galE gene of Neisseria meningitidis Group B, identifying two different homologous loci. Each of the loci was cloned and nucleotide sequence analysis revealed that both loci contained sequences similar to galE. One contained a functional galE gene and mapped to the capsule biosynthetic locus. The second contained only a partial galE-coding sequence, which did not express a functional gene product. A galE mutant meningococcal strain was constructed by transformation with an inactivated galE gene. Analysis of the LPS from the galE mutant strain revealed an apparent reduction in molecular weight and a loss of reactivity with monoclonal antibodies specific for structures known to contain galactose. These results are consistent with an essential role for galE in the incorporation of galactose into meningococcal lipopolysaccharide.

Glyoxalase enzymes I and II are involved in a detoxi®cation process consisting of conversion of reactive dicarbonyl compounds (e.g., methylglyoxal) to less reactive hydroxy acids. The structural gene for meningococcal glyoxalase I ( gloA) was identi®ed by screening an expression library with a rabbit antiserum. The meningococcal gloA gene consisted of 138 deduced amino acids, with a calculated mol. wt of 15.7 kDa. The DNA and deduced protein sequence of gloA was compared to known sequences of glyoxalase I enzymes and showed high homology with gloA of several eukaryotic and prokaryotic species. Insertion of a gloA-containing plasmid in Escherichia coli increased the host organism's tolerance to methylglyoxal from <2 mM to >4 mM, thus demonstrating its functional identity. A databank search also revealed the presence of a putative gloB gene, encoding glyoxalase II (GlxII), in the recently released genomic sequences of Neisseria meningitidis and N. gonorrhoeae.