CGSC Strain#: 5350
Strain Designation: MX419      Source of Strain: M.P. Oeschger
Sex: Hfr    Point of Origin#: 44   Map Position: 46.69   Direction of Marker Transfer: Counterclockwise
Chromosomal Markers: lacZ2210(Am), tsx-85, λ^-, serU74(ts,AS), gyrA21(NalR), relA1, rpsL183(strR), spoT1, thiE1
Strain Comments:

• supD74 (TS) is not very efficient in MX419. The rpsL183 allele inhibits the suppressor efficiency four-fold in this strain.
• 1.This strain was constructed to provide a source of the allele supD74(Ts). It transfers supD early in conjugation. Oeschger recommends using Val^R counterselection
• 2.in conjugational transfer from MX419.
• The presence of the suppressor can be monitored by checking for a Lac⁺ phenotype at 30C and a Lac^- phenotype at 40C.
• spoT1-- In addition to the 6bp insertion, there is a C to T transition resulting in an H257Y substitution.
• serU74(ts,AS) was formerly called supD74
• thiE1 was formerly called thi-1
• Am = amber(UAG) mutation
• AS = amber(UAG) suppressor
• NalR = Nalidix.acidResist.
• strR = streptomycin resist.
• ts = Temperature Sensitive

References:

• Oeschger, MP, SL Woods 1976. A temperature-sensitive suppressor enabling the manipulation of the level of individual proteins in intact cells. Cell 7(2):205-12.