Figure 2.

The Boltzmann device. Statistical potentials for the relative residue–residue orientations can be derived from probability density maps. The orientational probability density map (in units of 10⁻³) for Arg residues around Ile (A) and the reference map (B) corresponding to all of the side-chain types are used to build the statistical potential for the relative Ile–Arg orientations (C) in units of kT. These maps correspond to the second interaction shell [r_ij∈ (5.6 Å,9.2 Å)]. The smoothing effect of spherical harmonic synthesis (see Materials and Methods) is shown in D.