Addition of nucleotides leads to HIV-1 transcript elongation

Stable Identifier
Reaction [transition]
Homo sapiens
Related Species
Human immunodeficiency virus 1
Locations in the PathwayBrowser
SVG |   | PPTX  | SBGN
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout
This HIV-1 event was inferred from the corresponding human RNA Pol II transcription event. High-resolution structures of free, catalytically active yeast Pol II and of an elongating form reveal that Pol II elongation complex includes features like:
- RNA-DNA hybrid, an unwound template ahead of 3'-OH terminus of growing transcript and an exit groove at the base of the CTD, possibly for dynamic interaction of processing and transcriptional factors.
- a cleft or channel created by Rpb1 and Rpb2 subunits to accommodate DNA template, extending to Mg2+ ion located deep in the enzyme core
-a 50 kDa "clamp" with open confirmation in free polymerase, allowing entry of DNA strands but closed in the processive elongation phase.
The clamp is composed of portions of Rpb1,Rpb2 and Rpb3 , five loops or "switches" that change from unfolded to well-folded structures stabilizing the elongation complex, and a long "bridging helix" that emanates from Rpb1 subunit, crossing near the Mg2+ ion. The bridging helix is thought to "bend" to push on the base pair at the 3'-end of RNA-DNA hybrid like a ratchet, translocating Pol II along the DNA (Cramer et al.,2001; Gnatt et al.,2001).In addition to its dynamic biochemical potential, Pol II possess a repertoire of functions to serve as a critical platform of recruiting and coordinating the actions of a host of additional enzyme and proteins involved in various pathways.
Literature References
PubMed ID Title Journal Year
11313498 Structural basis of transcription: RNA polymerase II at 2.8 angstrom resolution.

Kornberg, RD, Bushnell, DA, Cramer, P

Science 2001
11313499 Structural basis of transcription: an RNA polymerase II elongation complex at 3.3 A resolution.

Kornberg, RD, Fu, J, Bushnell, DA, Cramer, P, Gnatt, AL

Science 2001
Inferred From
Name Identifier Synonyms
Human immunodeficiency virus infectious disease DOID:526 HIV infection
Cite Us!