Summary
When Escherichia coli K12(λ) lysogens are infected with heteroimmune λ phage, which are unable to replicate, general recombination between phage and prophage depends on the bacterial recF gene. It has been shown that in E. coli K12 postconjugational recombination, the RecF pathway only works with full efficiency if exonuclease I is absent (Clark 1973). However, results presented in this paper indicate that under conditions in which λ replication is blocked, the recombination pathway dependant on the recF gene is fully active in producing viral recombinants even, if the phage is Red+, in the presence of exonuclease I. In contrast, removal of λ exonuclease and β protein requires elimination of exonuclease I for an efficient RecF pathway. It is concluded that the Red system cooperates with the RecF pathway and that this cooperation involves overcoming the inhibitory effects of exonuclease I. In the absence of λ exonuclease, β protein stimulates recF-dependent recombination but does not suffice to prevent the negative effect of exonuclease I. In the presence of β protein, full efficiency of the RecF pathway can be obtained either via cooperation with λ exonuclease I or, if the viral exonuclease is defective, via inactivation of exonuclease I. Since activity of λ exonuclease appears necessary to overcome the inhibitory effects of exonuclease I, it is proposed here that λ exonuclease diverts material from the RecF pathway in a shunt reaction which allows completion of recF-initiated recombinational intermediates via a mechanism insensitive to exonuclease I.
When λ replication is allowed, the Rec system produces viral recombinants mainly via a recF-independent mechanism. However, a major contribution of the RecF pathway to λ recombination is observed after removal of the Red system and exonuclease I.
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References
Armengod M-E, Blanco M (1978) Influence of the recF143 mutation of Escherichia coli K12 on prophage λ induction. Mutat Res 52:37–47
Bachmann BJ (1972) Pedigrees of some mutant strains of Escherichia coli K-12. Bacteriol Rev 36:525–557
Bachmann BJ, Brooks Low K (1980) Linkage map of Escherichia coli K-12, Edition 6. Microbiol Rev 44:1–56
Bailone A, Blanco M, Devoret R (1975) E. coli K12 inf: A mutant deficient in prophage λ induction and cell filamentation. Mol Gen Genet 136:291–307
Blanco M, Armengod M-E (1976) Role of the bacterial and phage recombination systems and of DNA replication in genetic recombination of UV-irradiated phage lambda. Mol Gen Genet 146:51–54
Clark AJ (1973) Recombination deficient mutants of Escherichia coli and other bacteria. Annu Rev Genet 7:67–86
Clark AJ (1974) Progress toward a metabolic interpretation of genetic recombination of Escherichia coli and bacteriophage lambda. Genetics 78:259–271
Clark AJ, Volkert MR, Margossian LJ (1979) A role for recF in repair of UV damage to DNA. Cold Spring Harbor Symp Quant Biol 43:887–892
Devoret R, Blanco M (1970) Mutants of Escherichia coli K12 (λ)+ non-inducible by thymine deprivation. I. Method of isolation and classes of mutants obtained. Mol Gen Genet 107:272–280
Eisen HA, Fuerst CR, Siminovitch L, Thomas R, Lambert L, Pereira Da Silva L, Jacob F (1966) Genetics and physiology of defective lysogeny in K12(λ): Studies of early mutants. Virology 30:224–241
Enquist LW, Skalka A (1973) Geplication of bacteriophage λ DNA dependent on the function of host and viral genes. I. Interaction of red, gam, and rec. J Mol Biol 75:185–212
Gottesman ME, Yarmolinsky MB (1968) Integration-negative mutants of bacteriophage lambda. J Mol Biol 31:487–505
Horii ZI, Clark AJ (1973) Genetic analysis of the RecF pathway to genetic recombination in Escherichia coli K12: Isolation and characterization of mutants. J Mol Biol 80:327–344
Karu AE, Sakaki Y, Echols H, Linn S (1975) The γ protein specified by bacteriophage λ. J Biol Chem 250:7377–7387
Kushner SR, Nagaishi H, Templin A, Clark AJ (1971) Genetic recombination in Escherichia coli: The role of exonuclease I. Proc Natl Acad Sci USA 68:824–827
Lehman IR, Nussbaum AL (1964) The deoxyribonucleases of Escherichia coli. J Biol Chem 239:2628–2636
Manly KF, Signer ER, Radding CM (1969) Nonessential functions of bacteriophage λ. Virology 37:177–188
McEntee K, Weinstock GM, Lehman IR (1979) Initiation of general recombination catalyzed in vitro by the recA protein of Escherichia coli. Proc Natl Acad Sci USA 76:2615–2619
McMilin KD, Stahl MM, Stahl FW (1974) Rec-mediated recombinational hot spot activity in bacteriophage lambda. I. Hot spot activity associated with Spi- deletions and bio substitutions. Genetics 77:409–423
Miller JH (1972) Experiments in molecular genetics. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
Ogawa T, Tomizawa J (1968) Replication of bacteriophage DNA. I. Replication of DNA of phage lambda defective in early functions. J Mol Biol 38:217–225
Radding CM (1978) Genetic recombination: strand transfer and mismatch repair. Annu Rev Biochem 47:847–880
Shibata T, DasGupta C, Cunningham RP, Radding CM (1979) Purified Escherichia coli recA protein catalyzes homologous pairing of superhelical DNA and single-stranded fragments. Proc Natl Acad Sci USA 76:1638–1642
Shulman MJ, Hallick LM, Echols H, Signer ER (1970) Properties of recombination-deficient mutants of bacteriophage lambda. J Mol Biol 52:501–520
Stahl FW, McMilin KD, Stahl MM, Crasemann JM, Lam S (1974) The distribution of crossovers along unreplicated lambda bacteriophage chromosomes. Genetics 77:395–408
Stahl FW, Stahl MM, Malone RE (1978) Red-mediated recombination of phage lambda in a recA - recB - host. Mol Gen Genet 159:207–211
Templin A, Margossian L, Clark AJ (1978) Suppressibility of recA, recB, and recC mutations by nonsense suppressors. J Bacteriol 134:590–596
Thomas KR, Olivera BM (1978) Processivity of DNA exonucleases. J Biol Chem 253:424–429
Unger RC, Echols H, Clark AJ (1972) Interaction of the recombination pathways of bacteriophage λ and host Escherichia coli: Effects on λ recombination. J Mol Biol 70:531–537
Wilkins AS, Mistry J (1974) Phage lambda's generalized recombination system-study of the intracellular DNA pool during lytic infection. Mol Gen Genet 129:275–293
Willetts NS (1975) Recombination and the Escherichia coli K-12 sex factor F J Bacteriol 121:36–43
Zissler J, Signer E, Schaefer F (1971) The role of recombination in growth of bacteriophage lambda. I. The gamma gene. In: Hershey AD (ed) The bacteriophage lambda Cold Spring Harbor Laboratories, New York, p 455
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Communicated by W. Arber
Obra social de la Caja de Ahorros de Valencia (Director: S. Grisolía)
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Armengod, ME. Role of the recF gene of Escherichia coli K-12 in λ recombination. Molec. Gen. Genet. 181, 497–504 (1981). https://doi.org/10.1007/BF00428742
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DOI: https://doi.org/10.1007/BF00428742