Schematic of assembly of viral particles. (IMAGE) Institute of Science and Technology Austria Caption A schematic of the assembly of viral particles. Top: HTLV-1. The top layer (blue) organizes the immature lattice. Bottom: Other retroviruses (e.g. HIV-1). The bottom layer (orange) organizes the immature lattice. Credit © Nature Structural & Molecular Biology / Obr et al. Usage Restrictions Free to use when reporting about paper. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.