: Kaposi's sarcoma is the most commonly occurring cancer in persons infected with human immunodeficiency virus (HIV) and the acquired immunodeficiency syndrome (AIDS). Recent studies have provided strong evidence that Kaposi's sarcoma herpesvirus (KSHV or HHV-8) is the causative agent of Kaposi's sarcoma. To date, little is known about the detailed molecular biology of KSHV replication and pathogenesis. The purpose of the studies in this proposal is to understand the function of KSHV T1.1 RNA. Based on the hypothesis that T1.1 RNA is important for KSHV replication, it is important to know if it affects vira1 gene expression. It is also important to determine if T1.1 RNA directly interacts with viral or host cellular proteins. To address these questions, chemical modification mapping studies of the T1.1 RNA will determine accessible regions and identify on potential RNA protein binding motifs. This information will be used to design hammerhead ribozymes or anti-sense oligonucleotides that efficiently inhibit T1.1 RNA function. Affinity purification methods based on the T1.1 RNA mapping patterns will be used to identify cellular or viral proteins that form the T1.1 ribonucleoprotein complex.