Integration and excision of transducing lambda phages carrying RNA-polymerase genes
Mindlin, S.Z.; Kholodiĭ, G.I.; Kovalev, I.N.; Kiver, I.F.
Genetika 15(10): 1756-1766
1979
ISSN/ISBN: 0016-6758 PMID: 159205 Document Number: 140003
Transducing phages .lambda.rifd47, .lambda.rifd18 and .lambda.att80rifd35, arising from excision of phages .lambda. and .lambda.att80 (h.lambda.att-int-xis .vphi.80, imm.lambda.) from the locus bfe of E. coli K-12 and incorporating the adjacent region of chromosome rrnB-rpoB were studied. Hybrid att-sites of rifd phages (.DELTA.op') are different in their structure due to the insertion of the parental .lambda. and .lambda.att80 phages into different sites of the locus bfe. Besides, .lambda.rifd phages have a system of integration and excision of phage .lambda., while .lambda.att80rifd35 has inherited from phage .vphi.80. The integrational properties of phages rifd were expected to be different. These phages had a number of features in common, e.g., they can integrate, independently on the helper in the cells of recA strains; under these conditions the integration takes place not at the primary sites for phages .lambda. and .vphi.80, att.lambda. and att.vphi.80, respectively, but mostly at other chromosome regions; the insertion frequency fluctuates for different sites and is the highest near the locus bfe; curing frequencies and frequencies of exact excision are highly variable for different .lambda.rifd and .lambda.att80rifd prophage insertion sites. The unusual integration properties of transducing phages are supposed to be due to the incorporation of a region of bacterial chromosome rrnB-rpoB into phage genome and depend upon the functioning of an unidentified int-independent system of recombination.