The effect of certain Escherichia coli genes on the appearance of the TCS phenotype, conferred by plasmid RP4 with an integrated genome of the D3112 Pseudomonas aeruginosa phage
Kaplan, A.M.; Akhverdian, V.Z.; Krylov, V.N.
Genetika 29(8): 1288-1294
1993
ISSN/ISBN: 0016-6758 PMID: 8405972 Document Number: 416488
The possibility of the SOS system activation caused by introduction of a hybrid plasmid RP4::D3112 (where D3112 is a genome of the transposable phage of Pseudomonas aeruginosa) into Escherichia coli was examined. It has been shown previously that the presence of this plasmid confers to E. coli a so called TCS phenotype: E. coli (RP4::D3112) forms normal 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 shown 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 mutations (which cause correspondingly non-inducibility or constitutive expression of the SOS regulon). It was concluded therefore that the TCS phenotype is not related to induction of the SOS response. It was found also that the mutation to heat shock gene dnaJ (dnaJ259) is a cause for significant decrease in phage D3112 production in E. coli dnaJ259 (RP4::D3112) cells. The DNA hybridization data of labelled RP4 and D3112 DNA with total E. coli dnaJ259 (RP4::D3112) DNA suggest that the dnaJ259 probably affected the late D3112 functions.