CLONING AND CHARACTERIZATION OF A GENE FROM PASTEURELLA-HAEMOLYTICA A1 INVOLVED IN LIPOPOLYSACCHARIDE BIOSYNTHESIS

A Pasteurella haemolytica A1 gene involved in the biosynthesis of a mo iety on the core of the lipopolysaccharide molecule has been cloned an d characterized. Escherichia coil clones which carry this gene showed an alteration of its lipopolysaccharide migration profile on tricine S DS-PAGE and exhibited resistance to the core-specific phage U3. In add ition, lipopolysaccharide extracted from the E. coli clones was recogn ized by an anti-corespecific antiserum, but not by antiserum specific for the O antigen of P. haemolytica A1 lipopolysaccharide. Nucleotide sequence analysis of the cloned DNA identified an open reading frame ( lpsA) coding for a protein of 263 amino acids which showed significant homology with a Haemophilus influenzae type b lipooligosaccharide bio synthesis gene. PCR amplification of genomic DNA, using primers based on the P. haemolytica A1 lpsA sequence, yielded products from only the A biotypes of P. haemolytica.