Table 2. EC₅₀ values, i.e. the concentration of MetJ required to promote half-maximal formation of its complex with the F-metC DNA, in the presence and absence of ligands.

Entry	Liganda	EC50/nM
1	SAM, 1	96 ± 3
2	aza-SAM, 2	650 ± 40
3	12	540 ± 20
4	14	650 ± 40
5	15	154 ± 6
6	16	65 ± 3
7	no ligand	2900 ± 20

^aThe concentration of the ligands was 2 mM.