CGSC Strain#: 4359
Strain Designation: KL399      Source of Strain: M.C. Cappello
Sex: F- Chromosomal Markers: araC14, leuB6(Am), lacZ36, proC32, λ^-, hisF860(Stable), recA200(ts), thyA54, rpsE2115(SpcR), rpsL109(strR), malA38, xylA5, mtl-1, metE70, thiE1, deo-85
Strain Comments:

• The RecA(Ts) phenotype can be demonstrated only on a low-salt medium (0.5g per liter). This strain carries an uncharacterized mutation near his which confers a Mal⁺ phenotype.
• leuB6(Am)-- Suppressed by serU suppressor (supH)
• recA200(ts)-- is a temperature-sensitive mutation that can be tested for on plates of Luria Agar, modified to contain only 0.5 g/L NaCl, with 0.4 ug/ml mitomycin C at 42 C.
• thyA54-- Strains with this marker must have their medium supplemented with thymine (25ug/ml). This is true even for rich medium such as LB. Otherwise thymine starvation can lead to thymineless death.
• malA38-- : In Χ65 a Mal⁺ phenotype may have resulted from suppression of malA1, but in the absence of evidence, we show the mutations as malA38 and sup-78.
• deo-85-- is either deoB or deoC.
• proC32 was formerly called proC65
• thiE1 was formerly called thi-1
• Am = amber(UAG) mutation
• SpcR = spectinomycin resistant
• Stable = stable, non-reverting
• strR = streptomycin resist.
• ts = Temperature Sensitive

References:

• Lloyd, R.G., K.B. Low, G.N. Godson, E.A. Birge 1974. Isolation and characterization of an Escherichia coli K-12 mutant with a temperature-sensitive RecA- phenotype. J.Bacteriol. 120:407-415