TABLE 1.

Equilibrium binding and opening of PCNA by WT RFC and Walker A mutants

Reactions contained 10 nm clamp, 0–1600 nm (binding) or 0–400 nm (opening) clamp loader, and 0.5 mm ATP. ND, not determined.

Clamp loader	PCNA-MDCC binding Kd	PCNA-AF4882 opening
		Kd	Imax − Imin
	nm	nm
WT	1.2 ± 0.9	2.4 ± 2	0.86 ± 0.1
Rfc1GAT	9.2 ± 3	15 ± 1	0.67 ± 0.01
Rfc2GAT	20 ± 2	60 ± 30	0.13 ± 0.04
Rfc3GAT	130 ± 90	ND	0.072 ± 0.04
Rfc4GAT	29 ± 9	60 ± 20	0.11 ± 0.1
WT no ATP	540 ± 160	ND	0.048 ± 0.02