Characterization of the O antigen gene cluster and structural analysis of the O antigen of XXXX subsp. tularensis.

@entity558 @entity19 @entity5092 @entity24233 @entity31214
A gene cluster encoding enzymes involved in @entity558 O antigen biosynthesis was identified from the partial genome sequence of @entity24233 . All of the genes within the cluster were assigned putative functions based on sequence similarity with genes from O antigen biosynthetic clusters from other bacteria. Ten pairs of overlapping primers were designed to amplify the O antigen biosynthetic cluster by PCR from nine strains of @entity5092 . Although the gene cluster was present in all strains, there was a size difference in one of the PCR products between subsp. tularensis strains and subsp. holarctica strains. @entity558 was purified from @entity24233 and the O antigen was shown by mass spectrometry to have a structure similar to that of @entity31214 15. When @entity558 from @entity24233 was used to immunize @entity19 that were then challenged with @entity24233 , an extended time to death was observed.
