Partial support is requested for a meeting entitled "Structures and functions of nucleic acids, proteins and nucleoproteins" to be held in Austin, Texas on April 3-5, 1992. The meeting will encompass four main sessions: 1) DNA and RNA recombination - topology, intermediates and mechanisms 2) Topological problems in DNA replication 3) DNA bending -active and passive roles, and 4) Transcription factors- proteins-DNA and protein-protein interactions. Twenty-five outside speakers will attend, most of whom will pay their own travel expenses. NSF funds are requested for travel expenses of 25 young investigators, graduate student and postdoctoral fellows, from laboratories not represented by invited speakers. Approximately 75 local attendees from the University of Texas, Austin will also participate.