Search results
Results from the WOW.Com Content Network
Function of RNA polymerase II (transcription). Green: newly synthesized RNA strand by enzyme. RNA polymerase II (RNAP II and Pol II) is a multiprotein complex that transcribes DNA into precursors of messenger RNA (mRNA) and most small nuclear RNA (snRNA) and microRNA. [1] [2] It is one of the three RNAP enzymes found in the nucleus of ...
The preinitiation complex (PIC) is a large complex of proteins that is necessary for the transcription of protein-coding genes in eukaryotes and archaea.The PIC helps position RNA polymerase II over gene transcription start sites, denatures the DNA, and positions the DNA in the RNA polymerase II active site for transcription.
The positive transcription elongation factor, P-TEFb, is a multiprotein complex that plays an essential role in the regulation of transcription by RNA polymerase II (Pol II) in eukaryotes. [1] Immediately following initiation Pol II becomes trapped in promoter proximal paused positions on the majority of human genes (Figure 1).
Transcription preinitiation complex, represented by the central cluster of proteins, causes RNA polymerase to bind to target DNA site. The PIC is able to bind both the promoter sequence near the gene to be transcribed and an enhancer sequence in a different part of the genome, allowing enhancer sequences to regulate a gene distant from it.
RNA Polymerase II Transcription: the process of transcript elongation facilitated by disassembly of nucleosomes. RNAP from T. aquaticus pictured during elongation. Portions of the enzyme were made transparent so as to make the path of RNA and DNA more clear. The magnesium ion (yellow) is located at the enzyme active site.
The long poly-A tail is unique to transcripts made by Pol II. In the process of terminating transcription by Pol I and Pol II, the elongation complex does not dissolve immediately after the RNA is cleaved. The polymerase continues to move along the template, generating a second RNA molecule associated with the elongation complex. [1]
Mediator interacts with the pre-initiation complex, composed of RNA Polymerase II and general transcription factors TFIIB, TFIID, TFIIE, TFIIF, and TFIIH to stabilize and initiate transcription. [12] Studies of Mediator-RNA Pol II contacts in budding yeast have emphasized the importance of TFIIB-Mediator contacts in the formation of the complex.
DNA polymerase II (also known as DNA Pol II or Pol II) is a prokaryotic DNA-dependent DNA polymerase encoded by the PolB gene. [1] DNA Polymerase II is an 89.9-kDa protein and is a member of the B family of DNA polymerases. It was originally isolated by Thomas Kornberg in 1970, and characterized over the next few years.