Comparison of Wzy activity among repeating unit donors with variable lipid moieties. The numbers refer to the radioactivity of O-polysaccharide-PP-lipid against the total radioactivity in the paper chromatography assay [Number/100 = (total radioactivity of the chromatography paper – radioactivity of paper squares where input RU-PP-lipid was located)/total radioactivity of the chromatography paper]. The reactions were allowed to proceed for 4 hours with three replicates being performed for each lipid analog. Percentages shown are the means ± standard error of two independent experiments with triplicate determinations.