[The phenotype of rpi mutant of Pseudomonas aeruginosa phage-transposon D3112 expressed in a heterologous Escherichia coli host].

A clone of Escherichia coli II-16 with unique properties was isolated upon incorporation of hybrid plasmid RP4::D3112 with an integrated genome of phage-transposon D3112 Pseudomonas aeruginosa into E. coli C600 cells. The cells of this clone produce viable phage and are not sensitive to growth under low temperatures, which is characteristic of the majority of E. coli (RP4::D3112) clones with the genome of wild type phage. The clone E. coli II-16 contains phage genome both in an integrated state within the chromosome and in plasmid RP4. The properties of phage D3112 in the clone II-16 demonstrated that the phage carried a mutation. The mutation was designated RP4-phage interaction (rpi). The phenotypic effect of this mutation is expressed as phage inability to replicate in response to the presence of plasmid RP4 at 30 C (Tcs phenotype). The mutant rpi differs in its characters from the previously described mutants in the early regulator gene cip, the analog of the ner gene of E. coli phage Mu1, and from the known mutations in the A gene. Plasmid RP4::D3112 rpi exerts an inhibitory effect on the burst size of RP4::D3112 in E. coli.