We recently isolated a recombinant phage from a Haemophilus influenzae type b (Hib) library that assembles an oligosaccharide with an apparent molecular weight of 1400 (1.4 K) on a 4.1 K Escherichia coli lipopolysaccharide (LPS) structure, producing a 5.5 K LPS species that contains a KDO (2‐keto‐deoxyoctulosonic acid) epitope. Subcloning and deletional analysis of the 14 kb Haemophilus insert showed that three overlapping restriction fragments contained within a 7.2 kb pstl–Bam HI fragment sequentially modified an E. coli 4.1 K LPS structure, generating novel species of 4.5K, 5.1K and 5.5K. Only the 5.5K species contained the KDO epitope. We confirmed the relationship between the cloned genes and Hib lipooligosaccharide (LOS) biosynthesis by constructing a mutant that expressed an altered LOS. Thus, the Hib 7.2 kb Pstl‐Bam Hl restriction fragment contained a cluster of at least three genetic loci whose products acted sequentially in LOS biosynthesis.
|Original language||English (US)|
|Number of pages||6|
|State||Published - Oct 1991|
ASJC Scopus subject areas
- Molecular Biology