Table 1

Plasmid supercoiling measurements from relaxation experiments
Genotype
 Experimental treatment
 Plasmid σ
 Model ratio
gyrARparCR
 15 μg/ml Nor, 0 min
 -0.057
 1.0
gyrARparCR
 15 μg/ml Nor, 2 min
 -0.057
 1.0
gyrARparCR
 15 μg/ml Nor, 5 min
 -0.057
 1.0
gyrARparCR
 15 μg/ml Nor, 10 min
 -0.057
 1.0
gyrARparCR
 15 μg/ml Nor, 20 min
 -0.060
 1.0
gyrARparCR
 15 μg/ml Nor, 30 min
 -0.060
 0.9
gyrARparCR
 50 μg/ml Nor, 0 min
 -0.057
 1.0
gyrARparCR
 50 μg/ml Nor, 2 min
 -0.057
 1.0
gyrARparCR
 50 μg/ml Nor, 5 min
 -0.057
 1.0
gyrARparCR
 50 μg/ml Nor, 10 min
 -0.058
 1.0
gyrARparCR
 50 μg/ml Nor, 20 min
 -0.059
 1.0
gyrARparCR
 50 μg/ml Nor, 30 min
 -0.061
 0.9




gyrB+
 37°C
 -0.059
 1.0
gyrB+
 42°C, 2 min
 -0.059
 1.0
gyrB+
 42°C, 5 min
 -0.059
 1.0
gyrB+
 42°C, 10 min
 -0.059
 1.0
gyrB+
 42°C, 20 min
 -0.061
 1.0




gyrBTS
 37°C
 -0.044
 1.0
gyrBTS
 42°C, 2 min
 -0.023
 1.6
gyrBTS
 42°C, 5 min
 -0.016
 1.8
gyrBTS
 42°C, 10 min
 ND
 ND
gyrBTS
 42°C, 20 min
 0.000
 2.5




gyrA+parCR
 15 μg/ml Nor, 0 min
 -0.057
 1.0
gyrA+parCR
 15 μg/ml Nor, 2 min
 -0.025
 1.7
gyrA+parCR
 15 μg/ml Nor, 5 min
 -0.009
 2.2
gyrA+parCR
 15 μg/ml Nor, 10 min
 -0.006
 2.3
gyrA+parCR
 15 μg/ml Nor, 20 min
 -0.002
 2.4
gyrA+parCR
 15 μg/ml Nor, 30 min
 0.000
 2.5




gyrA+parC+
 50 μg/ml Nor, 0 min
 -0.057
 1.0
gyrA+parC+
 50 μg/ml Nor, 2 min
 -0.016
 1.9
gyrA+parC+
 50 μg/ml Nor, 5 min
 -0.002
 2.4
gyrA+parC+
 50 μg/ml Nor, 10 min
 0.000
 2.5
gyrA+parC+
 50 μg/ml Nor, 20 min
 0.007
 2.8
gyrA+parC+
 50 μg/ml Nor, 30 min
 0.016
 3.2
gyrA+parC+
 15 μg/ml Nor, 0 min
 -0.055
 1.0
gyrA+parC+
 15 μg/ml Nor, 10 sec
 -0.048
 1.1
gyrA+parC+
 15 μg/ml Nor, 25 sec
 -0.040
 1.3
gyrA+parC+
 15 μg/ml Nor, 45 sec
 -0.032
 1.5
gyrA+parC+
 15 μg/ml Nor, 1 min
 -0.027
 1.6
gyrA+parC+
 15 μg/ml Nor, 1.5 min
 -0.022
 1.7
gyrA+parC+
 15 μg/ml Nor, 2 min
 -0.017
 1.9
gyrA+parC+
 15 μg/ml Nor, 3 min
 -0.012
 2.1
gyrA+parC+
 15 μg/ml Nor, 4 min
 -0.008
 2.2
gyrA+parC+
 15 μg/ml Nor, 5 min
 -0.003
 2.4
gyrA+parC+
 15 μg/ml Nor, 7 min
 0.000
 2.5
gyrA+parC+
 15 μg/ml Nor, 10 min
 0.003
 2.6
gyrA+parC+
 15 μg/ml Nor, 15 min
 0.002
 2.6
gyrA+parC+
 15 μg/ml Nor, 20 min
 0.000
 2.5




ΔacrA
 0 μg/ml Novo, 0 min
 -0.057
 1.0
ΔacrA
 20 μg/ml Novo, 5 min
 -0.011
 2.1
ΔacrA
 50 μg/ml Novo, 5 min
 0.005
 2.7
ΔacrA
 200 μg/ml Novo, 5 min
 0.011
 3.0

pBR322 plasmid DNA was isolated from cells and analyzed by electrophoresis. Experimental treatments in bold indicate samples taken immediately before addition of drug or temperature shift, which were used as a reference for the following time points. Model ratios represent values derived from plasmid σ by taking the ratio of σ in each time point and dividing by σ in the reference, and scaling that value such that a sigma of 0 corresponds to a model ratio of 2.5. Nor, norfloxacin; Novo, novobiocin; SSG, supercoiling-sensitive gene; TS, temperature-sensitive. ND, not determined.

Peter et al. Genome Biology 2004 5:R87   doi:10.1186/gb-2004-5-11-r87