CGSC Strain#: 8177
Strain Designation: VS102     
Source of Strain: V.A. Stupina
Sex: F-
Chromosomal Markers: Δ(gpt-proA)62,
lacY1,
tsx-29,
glnX44(AS)
,
galK2(Oc)
,
λ-,
lacZp-topA76(L5F C662H),
cysB38,
zci-2234::cat,
Rac-0,
topB77::Tn5,
hisG4(Oc)
,
rfbC1,
kdgK51,
xylA5,
mtl-1,
argE3(Oc)
,
thiE1Strain Comments: - This strain is CamR and KanR, with inducible topA and deleted topB; it requires IPTG at all temperatures and will grow at 30-42C on L + 15 ug/ml Clam and 1 mM IPTG.
- 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.
- lacZp-topA76(L5F C662H)-- replaces promoter topAp of allele topA78(G65N W79S substitutions in TopoI) with lacZp, resulting in an IPTG requirement for expression.
- lacZp-topA76(L5F C662H)-- : poor growth at 30C in absence of IPTG; At 42C, TopoI level is low and more negative supercoiling is observed, but the strain grows if it is topB+.
- zci-2234::cat-- is an insertion of cam at a unique SphI site in region 5' (counterclockwise) of the topA gene
- Δ(gpt-proA)62 was formerly called proA2
- galK2(Oc) was formerly called gal2
- glnX44(AS) was formerly called su+II
- glnX44(AS) was formerly called supE44
- glnX44(AS) was formerly called glnV44
- rfbC1 was formerly called rfbD1
- thiE1 was formerly called thi-1
- = chloramphenicol resistant
- = kanamycin resistant
- AS = amber(UAG) suppressor
- L5F C662H = amino acid changes in TopoI
- Oc = ochre(UAA) mutation
References: - Stupina, V.A., J.C. Wang 2005. Viability of Escherichia coli topA mutants lacking DNA topoisomerase I. J.Biol.Chem. 280:355-360