Backbone dynamics of apo and holo FGF2 by NMR.

A) ¹H¹⁵N-HSQC cross peaks normalized intensity (I) upon sm27 binding vs residue number. Gray and black diamond refers to backbone amides, and glutamine, asparagine and arginine side chains, respectively. B) ¹H¹⁵N-HSQC cross peaks intensity variations plotted on FGF2 molecule. Blue (filled) and red (dotted) spheres indicate residues showing an increased and reduced intensity upon sm27 binding, respectively. The sphere radius is set according to the size of the variation. Side chains affected by intensity variations are shown in sticks. R129 and K144 side chains are shown in yellow sticks for clarity reasons. C) Modelfree analysis order parameters (S2) for the apo- and holo-FGF2 are reported in black and gray, respectively, as a function of the residue number. The black and gray straight lines represent the S2 average value for the apo and holo FGF2, respectively. S2 values are mapped on FGF2 structure in D and E for the apo and holo form, respectively. Color code: red for , where and are the average and the standard deviation for S2 values, respectively; orange for ; white for ; marine for ; blue for . Secondary structure elements are numbered for clarity purposes. F) and G) R2/R1rhovalues as a function of the residue number are reported for the apo and holo FGF2, respectively. The horizontal straight and dotted lines represent the average value and the average plus one standard deviation, respectively. H) Residues with R2/R1rho exceeding from one in the apo and holo FGF2 are mapped on the protein structure. Green spheres represent residues affected by conformational exchange in both the apo and holo form. Marine dotted spheres represent residues affected by conformational exchange only in the apo-FGF2 form. Red spheres represent residues affected by conformational exchange upon sm27 binding. Residues with R2/R1rho values affected by significant errors, either in the apo or in the holo form, are represented as dotted spheres.