CGSC Strain#: 7638
Strain Designation: BW25141/pKD20      Source of Strain: B.L. Wanner
Sex: F- Episome/Plasmid: pKD20
   Plasmid Markers/Mutations: repA101(ts), araBp-gam-bet-exo, oriR101, bla(ApR), araC , bla
   Plasmid Comment: Lambda Red recombinase expression plasmid. This plasmid includes 2154 nucleotides (31088-33241) of phage Lambda. 6078 basepairs. LESS EFFICIENT than pKD46. Send pKD46. Genbank AY048745, pKD20.
Chromosomal Markers: Δ(araD-araB)567, ΔlacZ4787(::rrnB-3), Δ(phoB-phoR)580, λ^-, galU95, ΔuidA3::pir⁺, recA1, endA9(del-ins)::FRT, rph-1, Δ(rhaD-rhaB)568, hsdR514
Strain Comments:

• Send pKD46 instead. It is more efficient than pKD20. pKD20 sequence is GenBank AY048745.
• Δ(araD-araB)567-- This deletion extends from ~25 bp upstream of the araB start codon to ~8 bp into the beginning of the araD gene
• ΔlacZ4787(::rrnB-3)-- : 4 tandem copies of the rrnB transcriptional terminator inserted by gene replacement into the region extending from near the SacII site near the N-terminus of lacZ through the promoter.
• ΔuidA3::pir⁺-- Allows the replication of plasmids with an R6Kγ origin of replication
• recA1-- : Missense mutation, altered isoelectric point. Sequenced: G to A for Nuc. 720 (Gly 160 Asp).
• rph-1-- is a 1 bp deletion that results in frameshift over last 15 codons and has polar effect on pyrE leading to suboptimal pyrimidine levels on minimal medium.(Jensen 1993 JBact.175:3401)
• Δ(araD-araB)567 was formerly called Δ araBAD_AH33
• Δ(rhaD-rhaB)568 was formerly called Δ rhaBAD_LD78
• endA9(del-ins)::FRT was formerly called endA_BT333
• ΔlacZ4787(::rrnB-3) was formerly called ::rrnB-4
• ΔlacZ4787(::rrnB-3) was formerly called Δ lacZ_WJ16
• ΔuidA3::pir⁺ was formerly called uidA(Δ MluI)::pir⁺
• ::rrnB-3 = 4 copies of rrnB inserted
• del-ins = deletion-insertion
• ApR = ampicillin resistant
• ts = Temperature Sensitive

References:

• Datsenko, KA, BL Wanner 2000. One-step inactivation of chromosomal genes in Escherichia coli K-12 using PCR products. Proc. Natl. Acad. Sci. U.S.A. 97(12):6640-5.