Enzymes leading to the nucleotide sugar precursors for exopolysaccharide synthesis in Burkholderia cepacia

Based on the chemical composition of the exopolysaccharide produced by the cystic fibrosis bacterial isolate Burkholderia cepacia IST408, we postulate d and confirmed, based on the specificity of enzymes detected in crude cell -free extracts, the pathway leading to the presumptive activated sugar prec ursors: UDP-D-glucose, UDP-D-galactose, UDP-D-glucuronic acid, GDP-D-mannos e, and GDP-D-rhamnose. Results also suggest that regulation of the expressi on of the mucoid phenotype in B. cepacia does not occur at the level of syn thesis of any of these enzymes. (C) 2000 Academic Press.