Figure 1.
Schematic showing the domains of full length and truncated topoisomerase II isoforms.
‘Y’ is the active site tyrosine, within the winged helix domain.
Figure 2.
Binding of full length and C-terminally truncated topoIIα and topoIIβ to a 40 bp DNA oligo.
(A) Typical anisotropy curve, measuring topoisomerase IIβ binding to oligo AB. (B) KD of binding (in nM). (C) Maximum anisotropy (Bmax). The average of at least three independent experiments is shown with error bars representing standard error from the mean. Statistical significance is indicated with * representing p<0.05, ** representing p<0.01 and *** representing p<0.001.
Table 1.
Binding of full length and C-terminally truncated topoIIα and topoIIβ to a 40 bp DNA oligo, showing binding affinity (KD) and maximum anisotropy (Bmax).
Figure 3.
Relative decatenation of full length and C-terminally truncated topoIIα or topoIIβ with different supporting metal ions.
Mg – Magnesium, Ca – Calcium, Mn – Manganese. For each protein, strand passage with magnesium ions was taken as 100% and other values calculated relative to this. The average of at least two independent experiments is shown, with error bars representing standard error from the mean. Statistical significance is indicated with * representing p<0.05 and *** representing p<0.001.
Table 2.
Relative decatenation of full length or C-terminally truncated topoIIα or topoIIβ with magnesium (Mg2+), Calcium (Ca2+) or Manganese (Mn2+) as supporting ion.
Figure 4.
The KD of binding to oligo AB (in nM) of full length topoIIα and topoIIβ, in the absence of metal or the presence of magnesium (Mg) or calcium (Ca) ions.
The average of at least two independent experiments is shown, with error bars representing standard error from the mean.
Table 3.
The KD of binding of topoIIα or topoIIβ (in nM) to DNA with no metal, 10 mM MgCl2, or 10 mM CaCl2.