Table 1.

Relative affinities of SET-TAFI-β and its deletion mutants for H3

SET/TAF-Iβ construct	Kd	Pull-down results
SET 1–277	0.15 ± 0.20	+
SET 1–210	0.13 ± 0.10	+
SET 76–210	0.14 ± 0.08	+
SET 76–185	0.10 ± 0.08	+
SET 110–277	0.16 ± 0.12	+
SET 110–210	n.d.	-

Binding of the various SET/TAF-Iβ deletion mutants with histone H3 was followed by monitoring the intensity of the fluorescence emitted by the tryptophan residues of SET/TAF-Iβ polypeptides upon addition of increasing amounts of calf thymus histone H3. The dissociation constant (K_d) for the complexes formed was estimated by non-linear regression analysis (KaleidaGraph, Synergy Software), as indicated in Methods.