On the left is integrase in its “intasome” structure of four identical four-part complexes (pink) that connect to create one 16-part complex that locks around viral DNA (blue). On the right is integrase in its simpler four-part complex (pink), as it interacts with viral RNA (green) inside an HIV capsid. Credit:Salk Institute uncovering its unexpected role in viral replication. This breakthrough provides a foundation for developing next-generation HIV drugs that could more eff