Colicin-Tolerant Mutants of Escherichia coli: Resistance of Membranes to Colicin El

Science  22 May 1970:
Vol. 168, Issue 3934, pp. 998-1000
DOI: 10.1126/science.168.3934.998


Colicin E1 blocks proline accumulation by membrane vesicles prepared from wild-type sensitive Escherichia coli. Two classes of mutant cells are unaffected by colicin. Vesicles from colicin-resistant strains are sensitive to colicin E1, whereas vesicles from colicin-tolerant strains are unaffected by colicin El. These results suggest that the colicin E1 receptor is on the cell membrane and that colicin-tolerant strains have altered membranes while colicin-resistant strains have altered cell walls.