Structural insights into the Cyclin T1-Tat-TAR RNA transcription activation complex from EIAV

The replication of many retroviruses depends on interactions between the viral TAR RNA element and Tat as well as Cyclin T1, a component of the cellular transcriptional elongation complex. Structural insights into this ternary complex now suggest that the equine infectious anemia virus TAR is engaged by both proteins with Tat in a helical conformation and that binding depends on flipping out specific bases in the TAR loop region.