Fig. 7

Pgm(692–768)* interacts with histone H3(1–19). a and b Superimposition of the ¹H-¹⁵N HSQC spectra recorded at 800 MHz and 20 °C of 100 μM ¹⁵N-Pgm(692–768) in the absence (black) and presence of 0.5 (red), 1 (orange), 2 (yellow), 4 (green), 6 (blue) and 10 (purple) molar equivalents of H3(1–19). The panels show resonances from residues from the N-terminal a and the α2 helix b regions that display significant chemical shift perturbations and/or broadening upon addition of H3(1–19). The residues that do not undergo chemical shift variations are annotated in grey and the others in black. c Relative intensities and, below, chemical shift perturbations of the resonances of Pgm(692–768)* in the presence of a 10-fold excess of H3(1–19). d One of the ensemble structures of Pgm(692–768)* showing the most affected residues in the presence of H3(1–19) in dark blue and pink. These are located in two main regions: the flexible N-terminal extension (695–702) and the α2 helix (743–753), in addition to Glu739 (light blue) in the preceding loop. Zn²⁺ ions are represented as spheres. e Determination of a dissociation constant (K_D) of 289 ± 70 μM using the chemical shift perturbations for residue E739