Final Activity Report Summary - HIV-CYCTAT-COMPLEXES (Structural studies on the HIV/EIAV Encoded Transcriptional Activator Tat in complex with TAR and the cellular components, Cyclin T1 and Cdk9)
The basic RNA-recognition motif of Tat adopts a helical structure whose flanking regions interact with a cyclin T-specific loop in the first cyclin box repeat. Together, both proteins coordinate the stem-loop structure of TAR. Our findings show that Tat binds to a surface on Cyclin T1 similar to where recognition motifs from substrate and inhibitor peptides were previously found to interact within Cdk-cyclin pairs.