Mutational analysis of the carboxy-terminal (YGX)(sub)4 repeat domain of CpsD, an autophosphorylating tyrosine kinase required for capsule biosynthesis in Streptococcus pneumoniae

Mutational analysis indicate that a CpsD truncation mutant containing no carboxy terminal (YGX)(sub)4 repeat domain is similar to a strain in which the entire cpsD gene is deleted, suggesting that the repeat domain is essential for CpsD activity and capsular polysaccharide production. Furthermore, results reveal thatthe tyrosine residues of the repeat domain are required for CpsD normal function.