TABLE 3.

Nucleotide exchange

Protein	No DNA		G/T
	koff with magnesium	koff without magnesium	koff with magnesium	koff without magnesium
	s−1	s−1	s−1	s−1
WT	0.007	0.016	0.24	0.04
2KA/6	NDa	ND	ND	ND
2/6KA	0.006	0.014	0.03	0.09
2KA/6KA	NDb	ND	ND	ND

^a ND, not determinable.

^b ND, not done.