[F-like genetic transfer factor pAP42].

Sensitivity of E. coli K-12 cells containing the transfer factor pAP42 to phages was examined to determine the frequency of the test factor transfer from one cell to another one. The data on the phage sensitivity and the frequency of transfer indicate that the test factor is F-like plasmid derepressed by the conjugation function. Study of incompatibility of the transfer factor pAP42 has shown its compatibility with plasmids of all 8 groups of F-incompatibility. This enables one to characterize this factor as a representative of a new FIX group of F-incompatibility.