Cover photograph (Copyright © 2005, American Society for Microbiology. All Rights Reserved.): Atomic model of dengue virus type 3 based on the crystal structure of the major envelope glycoprotein E. The packing of E molecules on the viral surface is derived from an electron cryomicroscopy image reconstruction of dengue virus type 2 (W. Zhang et al., Nat. Struct. Biol. 10:907-912, 2003). Residues on the viral surface that are not conserved in dengue virus type 2 are shown as purple spheres. Residues that are conserved in dengue, yellow fever, tick-borne encephalitis, and Japanese encephalitis viruses are shown as orange spheres. (See related article on page 1223.)