FIG. 4.
Edman degradation analysis of the N-termini of YopE1-7-Npt and YopE(A9C)1-7-Npt. (A and C) Purification of YopE1-7-Npt and YopE(A9C)1-7-Npt, respectively. Npt fusions were purified from Y. enterocolitica cell extracts after induction of type III secretion in low-Ca2+ medium by ion-exchange chromatography (MonoQ). Purification was followed by immunoblotting with antisera raised against Npt. Immunoblots and Coomassie-stained polyacrylamide gels separating peak fractions are shown. The stained band subjected to Edman degradation is outlined, and the N-terminal amino acid sequence assigned to each terminus is indicated. (B and D) Edman degradation of YopE1-7-Npt and YopE(A9C)1-7-Npt, respectively. The first seven cycles of analysis are shown, and peak residues are highlighted and listed on the right.