CGSC Strain#: 4180
Strain Designation: EM139      Source of Strain: E. Murgola
Sex: F- Chromosomal Markers: araC14, lacY1, tsx-57, glnX44(AS), galK2(Oc), rpsL20(strR), xylA5, mtl-1, thiE1, ilv-257, Ssl-139, tfr-5
Strain Comments:

• This strain must be grown in the presence of 200ug/ml streptomycin; otherwise, faster-growing revertants of the streptomycin-suppressible lethal mutation Ssl-139 will be selected.
• glnX44(AS)-- Mutation is a C to T transition at nucleotide 34 (3rd position of the anticodon)
• 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.
• Ssl-139-- streptomycin-suppressible lethal mutation.
• galK2(Oc) was formerly called gal₂
• glnX44(AS) was formerly called glnV44
• glnX44(AS) was formerly called su⁺_II
• glnX44(AS) was formerly called supE44
• thiE1 was formerly called thi-1
• AS = amber(UAG) suppressor
• Oc = ochre(UAA) mutation
• strR = streptomycin resist.

References:

• Murgola, EJ, EA Adelberg 1970. Streptomycin-suppressible lethal mutations in Escherichia coli. J. Bacteriol. 103(1):20-6.