Interaction of Bacterial and Lambda Phage Recombination Systems in the X-Ray Sensitivity of Escherichia coli K-12

AUTOR(ES)

Trgovčević, Željko

RESUMO

E. coli cells lysogenic for the thermoinducible prophage λcI857 can be transiently induced by a brief heat treatment. Although this treatment does not kill the cells, some λ products normally formed during vegetative phage development are made that can alter the response of host cells to x-irradiation by causing an increase in radioresistance. This increased resistance is particularly striking in the recombination-deficient recB-strain, which is normally much more radiosensitive than its recB+ parent. After pulse-heating at 42°, the survival curve of E. coli recB- lysogenized with λcI857 does not differ from that of the wild-type strain. Since λ red mutants do not increase the radioresistance of recB- strains, both λ red gene products, λ exonuclease and β-protein, are required to compensate for the missing recB product. Furthermore, phage-induced radioresistance also occurs in recB+ lysogens even when they carry λ red-, but not when the λ prophage is gam-. Thus, in wild-type cells, phage-induced radioresistance requires some interaction between the bacterial recB gene product (exonuclease V) and the phage λ-protein.

Documentos Relacionados

• X-ray Sensitivity and Repair Capacity of a polA1 exrA Strain of Escherichia coli K-12
• Effects on Genetic Recombination of Escherichia Coli K-12 Produced by X-Ray and Alpha-Particle Irradiation of the Female
• COMPARISON OF THE X-RAY SENSITIVITY OF BACTERIAL SPORES
• Lambda bacteriophage gene produces and X-ray sensitivity of Escherichia coli: comparison of red-dependent and gam-dependent radioresistance.
• Properties of a Deoxyribonucleic Acid Ligase Mutant of Escherichia coli: X-Ray Sensitivity