KY2750      Source of Strain:
F- Chromosomal Markers: thr-1
, (Ts)Strain Comments:
- 1.Growth on Minimal Medium plus supplements is slow and is stimulated by Casamino acids.
- 2.A nutritional shift-down has a deleterious effect and can be lethal.
- 3.It is necessary to check the TS character of the strain frequently in order to avoid overgrowth by revertants.
- CGSC Comment: We have found that on plates of Luria Agar (which contains 1% NaC1) this strain does not exhibit a TS phenotype at 42 degrees but is clearly TS at 45 degrees.
- If the Luria Agar is modified to contain only 0.1% NaC1, then the strain is clearly TS at 42 degrees.
- This strain, originally described as carrying dnaP18, a ts mutation near 85 min.,is now described as carrying a dnaG mutant, a suppressor of the dnaG mutation and an unmapped TS mutation.
- leuB6(Am)-- Suppressed by serU suppressor (supH)
- secA208-- : azi is now secA
- glnX44(AS)-- Mutation is a C to T transition at nucleotide 34 (3rd position of the anticodon)
- dnaG18-- : The dna mutation in this strain (originally dnaP18) was renamed dnaG2903 by Murakami et al.
- ``sdg-''2750-- is a mutation in KY2750 that suppresses the dnaG mutation.
- (Ts)-- : Unmapped temperature sensitive mutation
- fhuA2::IS2 was formerly called fhuA2
- glnX44(AS) was formerly called su+II
- glnX44(AS) was formerly called supE44
- glnX44(AS) was formerly called glnV44
- secA208 was formerly called azi-8
- thiE1 was formerly called thi-1
- xyl-7 was formerly called xylA7
- ::IS2 = Insertion of IS2
- Am = amber(UAG) mutation
- AS = amber(UAG) suppressor
- LamR = Lambda-resistant
- strR = streptomycin resist.
- Wada, C., T. Yura 1974. Phenethyl alcohol resistance in Eslcherichia coli. III. A temperature-sensitive mutation (dnaP) affecting DNA replication. Genetics 77:199-220
- Murakami, H., T. Nagata, W. Schwarz, C. Wada, T. Yura 1985. Novel dnaG mutation in a dnaP mutant of Escherichia coli. J.Bacteriol. 162:830-832