Transcription is the first step and the key control point in the pathway of gene expression.
Transcriptional regulation underlies development, oncogenesis, and fundamental events in pathogenesis, such as the transition from HIV pro-viral latency to viral replication. This lack of processivity is caused by synthesis of the TAR RNA whose coding sequence lies immediately downstream of the transcription start site. The strength of TAR RNA binding correlates well with the degree of response to Tat activation. Although diffraction data from these plate crystal has been obtained, further manipulations in the heavy metal derivatizing experiments proved to be unsuccessful. We have then tentatively aligned the predicted secondary structures of Rpb1 and Rpb2.