The effects of carboxypeptidase digestion on the function of colicin E3

The effects of carboxypeptidase digestion on the function of colcin E3 which had been demonstrated to be a complex of proteins A and B was investigated. It was indicated that removal of 7 amino acids from the C-terminal region of protein A has no significant effect on the interaction with the inhibitor, protein B, or with the specific cell surface receptor but does have an effect on the efficient interaction with the final target, ribosomes.