CARBOHYDRATE SPECIFICITY OF THE ESCHERICHIA-COLI P-PILUS PAPG PROTEINIS MEDIATED BY ITS N-TERMINAL PART

The adherence of pyelonephritic Escherichia coli isolates to mammalian host cells is mediated by the P-pili structures on the bacterial surf ace. The protein constituting the distal part of the pill structure, p apG, interacts with glycan receptors on the host cell. Variation in sp ecificity for different glycoconjugates between the isolates, that may reflect variation in host tropism, has been correlated to three diffe rent classes of papG. Truncated variants of the class I, II and III pa pG adhesins were produced as fusion protein in E. coli and analysed fo r carbohydrate binding. The results showed that both carbohydrate bind ing and specificity of the papG adhesin resided in a linear part of th e N-terminus of the protein.