Table 1.

¹⁵N relaxation and dynamics parameters for the Lys side-chains NH₃⁺ groups in the intermolecular ion pairs in the HoxD9 homeodomain-DNA complexes at 35 °C.

	Lys3 NH3+	Lys55 NH3+	Lys57 NH3+
Complex I a)
- 800 MHz -
15N R1 (s−1)	0.25 ± 0.01	0.43 ± 0.02	0.74 ± 0.01
15N R2,ini (s−1) c)	0.98 ± 0.05	1.98 ± 0.21	2.27 ± 0.04
1H-15N NOE	−2.40 ± 0.03	−2.72 ± 0.08	−3.00 ± 0.03
- 600 MHz -
15N R1 (s−1)	0.27 ± 0.01	0.59 ± 0.04	0.80 ± 0.02
1H-15N NOE	−3.07 ± 0.06	−2.94 ± 0.17	−3.17 ± 0.04
- Dynamics -d)
S2axis	0.22 ± 0.02	0.46 ± 0.06	0.48 ± 0.01
τf (ps)	3 ± 1	23 ± 2	113 ± 42
τi (ps)	222 ± 16	249 ± 42	82 ± 132
Complex II b)
- 800 MHz -
15N R1 (s−1)	0.29 ± 0.02	0.43 ± 0.03	0.33 ± 0.02
15N R2,ini (s−1) c)	1.16 ± 0.07	2.18 ± 0.26	1.76 ± 0.05
1H-15N NOE	−2.63 ± 0.06	−2.72 ± 0.09	−3.02 ± 0.13
- 600 MHz -
15N R1 (s−1)	0.29 ± 0.02	0.54 ± 0.08	0.36 ± 0.02
1H-15N NOE	−3.24 ± 0.10	−3.08 ± 0.20	−3.08 ± 0.13
- Dynamics -d)
S2axis	0.26 ± 0.02	0.49 ± 0.06	0.39 ± 0.01
τf (ps)	8 ± 4	26 ± 12	27 ± 7
τi (ps)	163 ± 43	184 ± 87	36 ± 19

^a)With Duplex I (see Figure 1).

^b)With Duplex II that contains a phosphorodithioate group at the ion pair with Lys57.

^c)The initial rate for intrinsically bi-exponential ¹⁵N transverse relaxation¹³ of NH₃⁺.

^d)Symbols are defined in Figure 2a. The molecular rotational correlation time and anisotropy were determined to be 10.6 ns and 2.1, respectively, from backbone ¹⁵N relaxation data.