CGSC Strain#: 4377
Strain Designation: KL414      Source of Strain: M.C. Cappello
Sex: F- Chromosomal Markers: araC14, leuB6(Am), lacZ36, proC32, λ^-, hisF860(Stable), recA56, thyA54, rpsE2115(SpcR), rpsL109(strR), xylA5, mtlA2, polA12(ts), thiE1
Strain Comments:

• This strain may carry malA38 and sup-78, an uncharacterized mutation near his which confers a Mal⁺ phenotype.
• This strain was originally grown in LB with 0.5% salt, thymine should also be added
• leuB6(Am)-- Suppressed by serU suppressor (supH)
• recA56-- Amino acid substitution Arg 60 Cys
• 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.
• polA12(ts)-- : sensitive to temperature and to low salt; altered pH optimum. Normal Exo levels. Totally defective in nick translation at 42C. recA56 polA12 are ts for growth.
• 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