ligated to the third hexose. Other hexose are often found attached to the outer core, branching from the main oligomer.

LPS that include lipid A and a complete core oligosaccharide (inner and outer) is referred to as "rough LPS."

Biosynthesis

The enzymes involved in core oligosaccharide synthesis are conserved among Escherichia coli and Salmonella. Pseudomonas aeruginosa has some unique enzymes.