TKL10      Source of Strain:
A. RorschOther Designations:
F- Chromosomal Markers: thr-1
, deoC1Strain Comments:
- This strain can grow on D-alanine and at 42 degrees it requires D-alanine supplementation. The strain originally carried an asp mutation, but has now lost its requirement for aspartic acid (H.J.W.Wijsman, personal communication).
- This strain does not use L-alanine as a carbon source at 28C or 42C.
- leuB6(Am)-- Suppressed by serU suppressor (supH)
- dadX20-- : Shown by Wasserman et al. to be complemented by a Salmonella dadB (in coli called dadX) gene.
- dadX21(ts)-- is used to signify a TS mutation near leu which H. Wijsman proposed to call qmeB, but is thought to be a TS dadX allele.
- thyA6-- Strains with this marker must have their medium supplemented with thymine (25ug/ml). This is true even for rich medium such as LB. Otherwise thymine starvation can lead to thymineless death.
- thyA6-- : Even with Luria or other complete media, supplement with thymine.
- alr-1(ts)-- at 42 C., in the presence of a mutation in the other alanine racemase gene, dadX, results in a requirement for D-alanine.
- dadX20 was formerly called msuA
- glnV44(AS) was formerly called supE44
- glnV44(AS) was formerly called su+II
- thiE1 was formerly called thi-1
- Am = amber(UAG) mutation
- AS = amber(UAG) suppressor
- ts = Temperature Sensitive
- Wijsman, HJ 1972. The characterization of an alanine racemase mutant of Escherichia coli. Genet. Res. 20(3):269-77.
- Wasserman, S.A., C.T. Walsh, D. Botstein 1983. Two alanine racemase genes in Salmonella typhimurium that differ in structure and function. J.Bacteriol. 153:1439-1450