Several species of streptococci produce extracellular polysaccharides in the form of
secreted exopolysaccharides or cell-associated capsules. Although the biological properties
and repeating unit structures of these polysaccharides are diverse, sequence analysis of the
genes required for their production has revealed a surprising degree of conservation among
five genes found in the capsule gene cluster of each of several polysaccharide-producing
streptococci. To determine the function of these conserved genes, we characterized a series …