[Changes in the nature of the sensitivity of an E. coli M strain carrying Inc-group R plasmids, to coliphages T3 and T7].
After the transfer of prototype plasmids R6K (IncX), R387 (IncK), R27 (IncH1) and T (IncN) to E. coli M nalr the appearance of histidine-dependent mutants (R27, T), histidine-leucine-dependent mutants (R6K), methionine-proline-dependent mutants (R387) was observed among the resulting transconjugates. The mutations of E. coli M nalr R+ cells induced by the introduction of the plasmids were accompanied by the transformation of the cells from the S-form into the R-form. In contrast to the prototrophs E. coli M nalr, the auxotrophs carrying plasmids R6K, R27, T acquired sensitivity to phage T7, and the methionine-proline-dependent mutant became sensitive to phages T and T7. The above-mentioned plasmids rendered E. coli M cells capable of synthetizing the donor pili. But the adsorption of phages T3 and T7 on the auxotrophic cells, both with and without plasmids, occurred due to their interaction with the cell-wall receptors.
D000327:Adsorption; D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000235:genetics*; D008854:Microscopy, Electron; D009154:Mutation; D011815:R Factors; D013604:T-Phages / Q000235:genetics* / Q000302:isolation & purification
Izmenenie prirody chuvstvitel'nosti shtamma E. coli M, nesushchego R-plazmidy nekotorykh Inc-grupp, k koli-fagam T i T7.