Structural elucidation of a novel core oligosaccharide backbone of the lipopolysaccharide from the new bacterial species Agrobacterium larrymoorei.

Agrobacterium larrymoorei is a Gram negative phytopatogenic bacterium which produces tumors on Ficus benjamina plants and differs from other agrobacteria both genetically and biochemically. The lipopolysaccharide (LPS) plays an important role in the pathogenesis of agrobacteria. Depending on the saccharide size, there are two kinds of LPS deriving from smooth and rough bacteria (S-LPS and R-LPS). A. larrymoorei produces only an R-form LPS, a lipooligosaccharide and in this article the first core structure was elucidated for an Agrobacterium species. This core is unusual since it lacks heptose residues and phosphate groups. A similar structure was found in Rhizobium spp., that are a group of bacteria that taxonomically are very close to agrobacteria.