Bacterial Strains

E. coli DH5α λpir

E.coli DH5αλpir strain contains the pir gene (lysogenized lpir phage lysogen) and is designed for cloning and propagation of plasmids with R6K origin of replication sequence (like pUTmini-Tn5 vectors). To transfer this plasmids directly from DH5αλpir donor strain to the recipient strain it is necessary to perform a triparental mating with a helper strain such as E. coliDH5α(pRK2013) (see Helper E. coli strains). The genotype of the strain is sup E44, ΔlacU169 (ΦlacZΔM15), recA1, endA1, hsdR17, thi-1, gyrA96, relA1, λpir phage lysogen.

E. coli S17-1 λpir

E.coli S17-1 λpir strain contains the pir gene (λpir). This strain have chromosomally integrated conjugal transfer functions (RP4 transfer functions), so when it is used as specific host strain into which the transposon vector DNA is transformed, the transfer occurs by biparental mating (a helper strain is not necessary). The genotype of the strain is TpR SmR recA, thi, pro, hsdR-M+RP4: 2-Tc:Mu: Km Tn7 λpir.

E. coli SM10 λpir

E.coli SM10 λpir strain contains the pir gene (lysogenized with λpir phage) and it is designed for cloning and propagation of plasmids with R6K origin of replication sequence (such as pUT mini-Tn5 vectors). The plasmids containing the R6K origin of replication require the R6K-spicific replication protein lpir gene for propagation. The genotype of the strain is KmR, thi-1, thr, leu, tonA, lacY, supE, recA::RP4-2-Tc::Mu, pir.

E. coli DH5a (pRK2013)

E.coli DH5a (pRK2013) strain contains the helper plasmid pRK2013, which provides tra and mob genes required to transfer the DNA cloned in pUTmini-Tn5 plasmids into the recipient strain, from donor strains, lacking these genes.  The genotype of the strain is supE44, ΔlacU169(ΦlacZΔM15), recA1, endA1, hsdR17, thi-1, gyrA96, relA1, pRK2013 (KmR oriColE1 RK2-Mob+ RK2-Tra+).

E. coli DH5a (pRK2073)

E. coli DH5a (pRK2073) strain contains the helper plasmid pRK2073, that provides tra and mob genes required to transfer the DNA cloned in pUTmini-Tn5 plasmids into the recipient strain, from donor strains lacking these genes. The genotype of the strain is supE44, ΔlacU169(Φ80lacZΔM15), recA1, endA1, hsdR17, thi-1, gyrA96, relA1, pRK2073 (StR oriColE1 RK2-Mob+ RK2-Tra+).