Table II. Summary of interactions between PCNA and FEN1.

	No DNA		On the DNA
	Bindinga		Bindingb		Nuclease activityc
	FEN1	fen1-ga	FEN1	fen1-ga	FEN1	fen1-ga
PCNA	100	0.4	100	<10	100	0.7
pcna-79	1	<0.1	80	n.d.	40	0.3
pcna-90	60	0.6	<10	n.d.	5	<0.1

^aBinding data from Table I and Figure 2.

^bBinding data from Figure 6 (in this assay the confidence limit for specific binding is 10% that of wild-type).

^cPCNA-stimulated FEN1 activity is from Figure 3. In all cases, wild-type activity or binding is set at 100.