CLONING AND EXPRESSION OF GENES ENCODING LIPID-A BIOSYNTHESIS FROM HAEMOPHILUS-INFLUENZAE TYPE-B

Genes similar to Escherichia coli lpx genes (encoding enzymes required for the biosynthesis of lipid A) have been cloned from Haemophilus in fluenzae type b using a hybridisation-based strategy. The derived amin o acid sequences are highly homologous to their E. coli counterparts. The genes appear in the same order in both E. coil and H. influenzae, but the intergenic regions differ. H. influenzae lpxA and lpxB have be en expressed in E. coli minicells and they encode proteins of the pred icted sizes. Both H. influenzae lpxA and lpxB are able to complement t emperature-sensitive mutants in the equivalent genes in E. coli. This provides evidence that the genetic manipulation of lpx genes to genera te altered lipid A molecules may be possible.