Fig 2.

(A) 600MHz ¹H-¹⁵N TROSY spectra of wild-type (blue) and M469pAcF/C575A (red) EIC. The NMR spectra were acquired at 37°C. Sample conditions were as follow: 400 μM EIC, 20 mM Tris, pH 7.4, 100 mM NaCl, 4 mM MgCl₂, 1 mM EDTA. Under these conditions EIC is present as a 70 kDa dimer (Patel et al., 2006). Resonance assignment for cross-peaks showing large chemical shift differences in the two EIC constructs is reported on the wild-type spectrum. (B) X-ray structure of the wild-type EIC dimer (PDB code 2HWG) (Teplyakov et al., 2006). The monomeric subunits are colored in cyan and orange. Residues whose resonances show large ¹H_N/¹⁵N chemical shift differences (>0.1 ppm) as a consequence of the M469pAcF and C575A mutations are indicated as blue spheres. M469 is shown as yellow sticks.