Structure of type 3Gn coaggregation receptor polysaccharide from Streptococcus cristatus LS4

The presence of a novel coaggregation receptor polysaccharide (RPS) on the dental plaque isolate Streptococcus cristatus LS4 was suggested by this strain’s antigenic and coaggregation properties. Examination of RPS isolated from strain LS4 by a combination of 2-dimensional and pseudo 3-dimensional single quantum heteronuclear NMR methods that included detection of 13C chemical shifts at high resolution revealed the following repeat unit structure: