CGSC Strain#: 7290
Strain Designation: LH18      Source of Strain: E.E. Howell
Sex: F' Episome/Plasmid: F128-20?
   Plasmid Markers/Mutations: lacIp-4000(lacI^Q), ΔlacZ58(M15)
   Plasmid Comment: This is presumably the same plasmid as F128-20, but its origin has not been tracked for this strain.
Chromosomal Markers: ΔfolA201::kan, Δ(pro-lac), glnV0(AS), thyA0, Δ(mcrB-hsdS)505
Strain Comments:

• Allele numbers for glnV, thyA mutations and pro-lac deletion are not known for parent strain NM522.
• The F' is presumably F128-20, although the origin of the plasmid has not been traced for parent strain NM522.
• ΔfolA201::kan-- : The entire folA structural gene and its promoter region is deleted and a kanR gene from pUC4K inserted by gene replacement. Requires thyA^- background.
• thyA0-- 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.
• Δ(mcrB-hsdS)505 was formerly called hsdΔ5
• Δ(mcrB-hsdS)505 was formerly called DE(hsdS-mcrB)5
• Δ(mcrB-hsdS)505 was formerly called hsd-555
• glnV0(AS) was formerly called supE-
• = kanamycin resistant
• AS = amber(UAG) suppressor
• M15 = alpha-complemented allele

References:

• Howell, E.E., P.G. Foster, L.M. Foster 1988. Construction of a dihydrofolate reductase-deficient mutant of Escherichia coli by gene replacement. J.Bacteriol. 170:3040-3045