CGSC Strain#: 4389
Strain Designation: KL304      Source of Strain: M.C. Cappello
Other Designations: KL303
Sex: F- Chromosomal Markers: Δ(gpt-proA)62, lacY1, glnX44(AS), glnS1(ts), galK2(Oc), λ^-, purB15, hisG4(Oc), rpsL35(strR), xylA5, mtl-1, thiE1
Strain Comments:

• glnS1 is a temperature-sensitive mutation. Growth stops immediately at 42 degrees C. This strain was made in the same way as was KL303 and is probably identical to KL303.
• hours of incubation. At 44 degrees C, the temperature sensitivity is more clear-cut. The glnS mutation reverts. The strain should be cloned and tested before use.
• This strain is temperature-sensitive at 42 degrees only on a medium containing a low salt concentration (e.g., Luria Agar modified to contain only 0.5% NaC1) and plates should be examined after 9
• glnX44(AS)-- Mutation is a C to T transition at nucleotide 34 (3rd position of the anticodon)
• glnS1(ts)-- is a temperature-sensitive mutation. Growth stops immediately at 42 degrees C. This allele reverts and the strain should be cloned and tested before use.
• galK2(Oc)-- is a GAA(glu) to TAA(ochre) mutation, residue 134. Oller et al.1993. Apparently non-suppressible, since all revertants found were at the ochre site.
• Δ(gpt-proA)62 was formerly called proA2
• galK2(Oc) was formerly called gal₂
• glnX44(AS) was formerly called su⁺_II
• glnX44(AS) was formerly called supE44
• glnX44(AS) was formerly called glnV44
• thiE1 was formerly called thi-1
• AS = amber(UAG) suppressor
• Oc = ochre(UAA) mutation
• strR = streptomycin resist.
• ts = Temperature Sensitive

References:

• Korner, A, BB Magee, B Liska, KB Low, EA Adelberg, D Soll 1974. Isolation and partial characterization of a temperature-sensitive Escherichia coli mutant with altered glutaminyl-transfer ribonucleic acid synthetase. J. Bacteriol. 120(1):154-8.