TABLE 2.

Observed rates for PCNA binding and opening by WT RFC and Walker A mutants

Reactions contained 20 nm labeled clamp, 200 nm clamp loader, and 0.5 mm ATP. ND, not determined.

Clamp loader	PCNA-MDCC binding kobs	PCNA-AF4882 opening kobs
	s−1	s−1
WT	8.3 ± 0.4	0.63 ± 0.04
Rfc1GAT	4.3 ± 0.3	0.36 ± 0.09
Rfc2GAT	4.5 ± 0.2	0.57 ± 0.2
Rfc3GAT	2.7 ± 0.2	0.70 ± 0.51
Rfc4GAT	3.0 ± 0.1	2.1 ± 1.8
WT no ATP	8.5 ± 0.7	ND