ABSTRACT, CORE 1 Core 1 (Voth and Forli, Leads) will provide an extensive and integrated computational capability in support of the science of the B-HIVE Projects. Many processes in HIV-1 that involve proteins, nucleic acids, and/or membranes are inherently multiscale, spanning multiple time and length scales, which vary from the molecular to nanoscopic to mesoscopic. Therefore, in Aim 1 bottom-up multiscale computational methods will be developed and implemented that characterize many-protein assembly processes in the HIV-1 lifecycle. To understand in greater detail the specific physical mechanisms which drive macromolecular interactions of HIV proteins with host factors and nucleic acids, in Aim 2 all-atom molecular dynamics simulations, together with protein-protein docking and kinetic modeling, will be used to build models of HIV proteins interacting with their partners. In order to support the B-HIVE Projects through computational structure-based pipelines and tools for the analysis of targets of interest, Aim 3 will provide well-established computational tools and methods that will also be further developed and extended. All three Aims complement one another and each Aim will provide important input to the other two Aims in an integrated fashion. Overall, Core 1 will extend and develop a set of powerful computational tools in support of the B-HIVE Projects. The Core will also provide valuable new resources for the overall HIV research community and beyond. 1