Identification of Streptococcus pneumoniae Cps2C residues that affect capsular polysaccharide polymerization, cell wall ligation, and Cps2D phosphorylation

A number of single amino acid substitutions throughout Streptococcus pneumoniae Cps2C were found to affect its function and confer either a mucoid or a small colony phenotype. These mutants exhibit significant changes in capsular polysaccharide (CPS) profile relative to that of wild-type pneumococci. The introduced mutations affect either polymerization or ligation of CPS to the cell wall and/or Cps2D phosphorylation.