Table 4.

Structural comparison of various TetR structures

	TetR–aptamer complex
			Inter-residue distances between identical residues (Cα-positions) in the superimposed complexes [Å]c
	r.m.s.d. EBDs [Å]a	r.m.s.d. NBDs [Å]b	Residue 55 on helix H4	Residue 12 on helix H1	Residue 42 on helix H3
TetR–TAP1 complex (PDB entry: 3ZQF, (37))	1.07	1.01	0.37	0.70	1.52
TetR–DNA complex (1QPI)	1.03	1.97	0.48	0.71	2.16
Tc-bound TetR (2TCT)	1.48	2.55	2.09	2.53	2.76
TetR–TIP complex (2NS8)	1.27	2.91	1.49	2.46	3.16

^aR.m.s.d. values obtained upon superposition of the two EBDs, only. Please see the Materials and Methods section for details.

^bValues obtained for the comparison of the orientation of the NBDs between the different complexes after the coordinates of the EBDs have been superimposed.

^cDistances occur twice, and average values are reported.