EFFECTS OF SOME ESCHERICHIA-COLI GENES ON MANIFESTATION OF TCS PHENOTYPE CONFERRED BY PLASMID RP4 WITH THE INTEGRATED PHAGE D3112 OF PSEUDOMONAS-AERUGINOSA

The possibility of the SOS system activation caused by introduction of a hybrid plasmid RP4=D3112 (where D3112 is a genome of the transposab le phage of Pseudomonas aeruginosa) into Escherichia coli was examined . It has been shown previously that the presence of this plasmid confe rs to E. coli a so called TCS phenotype: E. coli (RP4=D3112) forms nor mal colonies and grows at 42-degrees-C but does not divide and becomes filamentous at 30-degrees-C, probably because of E. coli DNA damages generated in the course of D3112 replication-transposition. It was sho wn that the level of prophage lambda induction is not elevated during the growth of E. coli (lambda) (RP4=D3112) cells at 30-degrees-C. The character of the TCS phenotype was not affected by lex A3 or lex A51 m utations (which cause correspondingly non-inducibility or constitutive expression of the SOS regulon). It was concluded therefore that the T CS phenotype is not related to induction of the SOS response. It was f ound also that the mutation to heat shock gene dnaJ (dnaJ259) is a cau se for significant decrease in phage D3112 production in E. coli dnaJ2 59 (RP4=D3112) cells. The DNA hybridization data of labelled RP4 and D 3112 DNA with total E. coli dnaJ259 (RP4=D3112) DNA suggest that the d naJ259 probably affected the late D3112 functions.