Electron microscopy of the Pfu Hjm-DNA complex. (A) Representative electron microscopic images of the complex. (B) The sequence and structure of the 3' overhang DNA. (C) Class averages of the Hjm-DNA complex, obtained from 3599 particles. The box size is 204 Å. (D) Single particle 3D reconstruction of the complex. Surface representations of the complex are shown from two orthogonal orientations. The atomic structure of the Hjm protein, shown as a cyan ribbon, is fitted into the density. The double-stranded DNA molecule, colored magenta, is fitted to the protruded region. (E) Comparison with the crystal structure of the A. fulgidus Hel308-DNA complex. The A. fulgidus binary complex, shown as a green and yellow ribbon, was fitted to the map using the Hel308 protein, and the location of the protruded double-stranded DNA is shown for comparison.