Rev
Tat
Vif
Integrase
Proteomics
Env
Nef

Tat

The HIV regulatory protein Tat enhances transcription from the viral promotor by increasing processivity of RNA polymerase II (RNAP II) complexes. Tat binds to an RNA site (TAR) on transcripts and recruits other cellular proteins including the elongation factor P-TEFb, which is competed away from an alternate complex with HEXIM1-7SK snRNA. The Tat project, headed by Dr. Alan Frankel, extends and builds upon previous studies by Dr. Frankel and other HARC Center members on the Tat-TAR system, including extensive characterization of the involved proteins and structural efforts with outside collaborators that resulted in two atomic resolution structures of TAR RNA complexed with the arginine rich motif (ARM) of Tat or arginamide--the only structures of TAR binary complexes to date.

The Tat project relies upon the considerable resources within the center to express the necessary proteins and determine the structures of Tat with its nucleic acid and protein partners, using a variety of structural approaches. Ultimately, the goal is to understand the conformational changes that allow the various binding reactions, as well as the structural basis of transcriptional activation by Tat.