Pol II is the central component of the basal RNA polymerase II transcription machinery.
It is composed of mobile elements that move relative to each other.
The CTD is an RNAPII-specific protein segment consisting of repeating heptads with the consensus sequence Y that has been shown to be extensively post-transcriptionally modified in a coordinated, but complicated, manner.
During transcription elongation, Pol II moves on the template as the transcript elongates. Formation of HIV elongation complex in the absence of HIV Tat. RPB1 is part of the core element with the central large cleft, the clamp element that moves to open and close the cleft and the jaws that are thought to grab the incoming DNA template. At the start of transcription, a single-stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol II. RNA Pol II CTD phosphorylation and interaction with CE during HIV infection. In this paper, we examine results and implications of recent studies related to modifications of the CTD and the respective enzymes; we also survey characterizations of new CTD-binding proteins and their associated processes and new information regarding known CTD-binding proteins.Finally, we bring into focus new results that identify two additional CTD-associated processes: nucleocytoplasmic transport of m RNA and DNA damage and repair.