Relationship between Colicinogenic Factors E1 and V and an F Factor in Escherichia Coli.

Kahn, Phyllis L. (Princeton University, Princeton, N.J.), and Donald R. Helinski. Relationship between colicinogenic factors E(1) and V and an F factor in Escherichia coli. J. Bacteriol. 88:1573-1579. 1964.-Colicinogenic factors are the genetic determinants for colicin production in enteric bacteria. An examination of the relationship of two colicinogenic factors, colE(1) and colV, to the F factor of fertility in Escherichia coli revealed that the colE(1) factor does not have the properties of a fertility factor, whereas the colV factor appears to possess a genetic determinant of fertility (F(v)). Cells containing colE(1) alone do not recombine with F(-) strains, whereas V(+)F(v) (+) strains can recombine, but at a lower frequency for certain markers than cells containing the F factor from E. coli. Strains possessing the colV factor can transfer the V(+) and F(v) (+) properties to an F(-) recipient, whereas strains harboring colE(1) alone are not able to transfer this factor. When a V(+)F(v) (+)E(1) (+) strain is used as a donor, recipients show F(v) (+) sexuality characteristics only if they also acquire the ability to produce colicin V. The colV factor is transferred at lower efficiency to F(+) than to F(-) strains, whereas the transfer of colE(1) is equally efficient to both. In addition, the V(+)F(v) (+)F(+) colonies isolated segregate V(+)F(v) (+)F(-) and V(-)F(v) (-)F(+) cells at high frequency, indicating an incompatibility between the colV and F factors. Finally, under the conditions employed, acridine orange does not remove the colE(1) factor, but will remove the colV factor from colicinogenic cells. In every case tested, the V(+) and F(v) (+) characteristics are removed simultaneously by the acridine orange treatment.