CGSC Strain#: 4297
Strain Designation: KL282      Source of Strain: M.C. Cappello
Sex: Hfr    Point of Origin#: 2A   Map Position: 12.20   Direction of Marker Transfer: Counterclockwise
Chromosomal Markers: fhuA22, phoA4(Am), serS16, serC13, ompF627(T2R), serU132(AS), fadL701(T2R), relA1, pitA10, spoT1, rrnB-2, mcrB1, creC510
Strain Comments:

• 1.The mutation serS14 is partially or completely reverted in this strain. The serine tRNA synthetase is no longer temperature-sensitive, but is reduced in activity 2-3 fold. Since there is
• 2.some doubt as to whether or not the serS locus is reverted to wild type, this reversion has been given the mutant allele designation serS16. We have been informed that KL282 will grow
• 3.on complete medium at both 30 and 37 degrees but will not grow on minimal medium + serine at 37 degrees, due to the presence of an unidentified temperature-sensitive mutation which is not at the
• 4. serS locus. We also have a report that the strain responds better to a mixture of glycine plus pyridoxine than it does to serine alone.
• phoA4(Am)-- is Garen's phoAS26 . It is suppressed by leuX151, glnV33(=supE33) and serU132(=supD32).
• spoT1-- In addition to the 6bp insertion, there is a C to T transition resulting in an H257Y substitution.
• rrnB-2-- : loss of spacer loop sequence
• creC510-- The constitutive phenotype is due to an R77P amino acid substitution
• creC510 was formerly called phoM510
• serU132(AS) was formerly called supD32
• serU132(AS) was formerly called Su1⁺
• = partial revertant
• Am = amber(UAG) mutation
• AS = amber(UAG) suppressor
• Const = constitutive
• T2R = T2 Resistant

References:

• Low, B, F Gates, T Goldstein, D Soll 1971. Isolation and partial characterization of temperature-sensitive Escherichia coli mutants with altered leucyl- and seryl-transfer ribonucleic acid synthetases. J. Bacteriol. 108(2):742-50.