The secondary structure (a), SAXS molecular envelope (b) and RDC-periodicity correlation fits (c) of H3e, an extended construct of H3. In (a), four inserted basepairs and a mutation, A61 to C61, compared to H3, are marked in red. In (b), two views of the SAXS molecular envelope of H3e (cyan) and the overlays with that of H3 are displayed. In (c), the best simultaneous fit yields that the orientations and phases of H3a and H3b are (6°, 57°, 307°) and (16°, 256°, 180°), respectively, and an angle between H3a and H3b is 158°.