HT306      Source of Strain:
F- Chromosomal Markers: thr-1
, cadA2Strain Comments:
- 1.Demonstration of the Spe- phenotype requires care. Polyamines may be present even in purified agar, on glassware not acid-washed, on some plasticware and in rust-inhibitors in autoclave steam.(pers.comm.,H.Tabor).
- 2.The strain does require spermidine for optimum growth, but it may be apparent only with growth curves performed in liquid media, using spermidine-starved cells as an inoculum (pers.comm.,B.Weiss),using precautions to avoid contaminating polyamines.
- 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.
- ampCp-1-- is a promoter mutation; AmpC+ strains carrying this allele produce about 10X the amount of beta lactamase found in wild-type strains. In absence of other amp alleles, use 10-15 ug/ml Amp.
- ampCp-1 was formerly called ampA1
- Δ(gpt-proA)62 was formerly called proA2
- galK2(Oc) was formerly called gal2
- glnV44(AS) was formerly called supE44
- glnV44(AS) was formerly called su+II
- thiE1 was formerly called thi-1
- AS = amber(UAG) suppressor
- Oc = ochre(UAA) mutation
- strR = streptomycin resist.
- Tabor, H., E.W. Hafner, C.W. Tabor 1980. Construction of an Escherichia coli strain unable to synthesize putrescine, spermidine, or cadaverine: characterization of two genes controlling lysine decarboxylase. J.Bacteriol. 144:952-956