Table 3.

Dimerization equilibrium constants of bacterial and phage repressors.

organism	Repressor name	KD	Method	Ref.
λ phage	cI	5.6 nM	Radioactive labeling and gelfiltration	8
λ phage	Cro	3 μM	Radioactive labeling and gelfiltration	9
E. coli	LacR	~ 10 pM	Estimate from observed protein-DNA ka at different concentrations	10
S. aureus phage ϕ11	cI	< 10 nM*	Gelfiltration	11
SaPIbov1	Stl	0.12 nM  ~ 1 pM	BLI BLI and DUT inhibition#	In this work
ShoCI794_SEPI	Stl	~ 1 pM	BLI and DUT inhibition #	In this work

*Repressor forms significant amount of dimers in solution at 10 nM repressor concentration.

^#Estimated assuming no competition of substrate binding.