Figure 2.

2D strip plots from 3D (H)CCH-TOCSY spectra of IscU acquired at 600 MHz (¹H). The NMR sample contained 1 mM [U-¹³C, ¹⁵N-Pro]-IscU, 50 mM Tris-HCl (pH 8.0), 5 mM DTT, 150 mM NaCl, 50 μM DSS, and 50 μM NaN₃ in 10% D₂O. 2D strips were taken at the chemical shifts of the prolyl ¹H^α, shown at the top of each strip. (a) Spectrum of the S-state of IscU stabilized as the Zn²⁺ complex at 25 °C. (b) Spectra of the D-state of IscU acquired at 45°C.