Studies of colicin action on wall-less stable L-forms of Escherichia coli. III. A colicin-tolerant mutant in a wall-less stable L-form.

The conversion of a tol III Escherichia coli mutant, tolerant to colicins E2, E3, Ia and K, into protoplast-like stable L-form makes it sensitive to colicins E2, Ia and K. Its original sensitivity to colicin E1 and tolerance to E3 are preserved in this cell form. Thus, rods of this mutant are not truly tolerant to colicins E2, Ia and K, but "pseudotolerant": their wall receptors have been turned out to "nonlethal" ones by the mutation in question.