Moreover, we checked the influence of the Box3 conformation on the scattering curve by calculating the scattering profile of pseudomodels of the complex. In these pseudomodels, the N-terminal region of N TAIL is in the same conformation as in the credo model shown in Figure  2C . The only difference concerns the orientation of Box3, which points out of the complex, in different solventexposed conformations. Noteworthy, the theoretical scattering curves calculated from these pseudomodels using CRYSOL (Svergun et al. 1995) poorly fit with the experimental curve, with an average 2 of $ 7.0 (data not shown). This confirms that the C terminus of N TAIL does contribute to the observed scattering profile, thus attesting the reliability of the model provided by CREDO.