Fig. 1. Electron density map reveals ribosome-bound eIF5A. Views of the 80S ribosome/eIF5A structure.
(a) Unbiased Fo-Fc electron density map, contoured at 3σ, reveals the hypusine conformation and allows nearly complete modeling of ribosome-bound eIF5A. Yellow cartoon traces the Cα atoms, red sticks show hypusine. (b) View of the 60S ribosomal subunit shows the eIF5A-binding site and eIF5A interactions with two dynamic ribosome features—the L1-stalk and helix H69 of the 25S rRNA. The inset shows the view orientation. (c), The hypusine-binding site. The hypusine conformation is stabilized by extensive contacts with the 25S rRNA.