C-Terminal Domain Swapping of SSB Changes the Size of the ssDNA Binding Site

Table 2

ssDNA binding properties of KpSSB, StSSB, PaSSB, KpSSBnStSSBc, and KpSSBnPaSSBc as analyzed by EMSA.

Protein	DNA	[Protein]50 (nM)	Complex number
KpSSB	dT20	ND	0
	dT25	200 ± 20	1
	dT35	220 ± 30	1
	dT45	100 ± 10	1
	dT50	110 ± 20	1
	dT55	100 ± 20	2
	dT60	100 ± 10	2
StSSB	dT15	650 ± 120	1
	dT20	450 ± 80	1
	dT30	420 ± 60	1
	dT40	420 ± 80	1
	dT45	440 ± 60	2
	dT50	440 ± 50	2
PaSSB	dT20	ND	0
	dT25	1700 ± 250	1
	dT35	950 ± 180	1
	dT45	780 ± 160	1
	dT55	820 ± 90	1
	dT60	810 ± 110	2
	dT65	550 ± 70	2
KpSSBnStSSBc	dT15	260 ± 60	1
	dT20	110 ± 20	1
	dT40	120 ± 20	1
	dT45	160 ± 20	2
KpSSBnPaSSBc	dT20	ND	0
	dT25	390 ± 60	1
	dT40	220 ± 30	1
	dT55	230 ± 30	1
	dT60	230 ± 30	2

[Protein]₅₀ was calculated from the titration curves of EMSA by determining the concentration of the protein (μM) needed to achieve the midpoint value for input ssDNA binding. For some oligonucleotides, input ssDNA binding was the sum of the intensities from the two separate ssDNA-protein complexes. Errors are standard deviations determined by three independent titration experiments.