Table 1.

Steady-state fluorescence data during PCNA loading

Loading steps	ATP as cofactor			ATPγS as cofactor
	ET*	EO†	R0, Ň	ET	EO	R0, Å
PCNA	0.952 ± 0.003	0.95	13	0.952 ± 0.003	0.95	13
PCNA, RFC, nucleotide	0.658 ± 0.008	0.07	34	0.71 ± 0.03	0.23	27
PCNA, RFC, nucleotide, DNA	0.82 ± 0.01	0.56	21	0.72 ± 0.02	0.26	26
PCNA, RFC, nucleotide, DNA, SA§	0.91 ± 0.01	0.83	17	0.71 ± 0.01	0.23	27

*The averaged energy transfer efficiency of all three subunit interfaces.

^†The energy transfer efficiency of open interface.

^‡The calculated distance of the open subunit interface.

^§SA, streptavidin.