transcription elongation factor complex

Definition

Target type: cellularcomponent

Any protein complex that interacts with RNA polymerase II to increase (positive transcription elongation factor) or reduce (negative transcription elongation factor) the rate of transcription elongation. [GOC:jl]

The transcription elongation factor complex is a multi-protein assembly that plays a crucial role in the process of transcribing DNA into RNA. It binds to RNA polymerase II, the enzyme responsible for transcription, and helps it to overcome obstacles and continue transcribing DNA. The complex is composed of several subunits, each with its own specific function.

**Core components:**

* **RNA polymerase II:** The central enzyme responsible for synthesizing RNA using DNA as a template. It contains 12 subunits, including the two largest subunits, RPB1 and RPB2.
* **Transcription elongation factors (TEFs):** These proteins bind to RNA polymerase II and modulate its activity during elongation. Examples include:
* **TFIIF:** This complex facilitates the initial recruitment of RNA polymerase II to the promoter and is also involved in the transition from initiation to elongation.
* **Spt5 and Spt6:** These proteins form a heterodimer that associates with RNA polymerase II and plays a role in regulating the elongation process, including pausing and re-initiation.
* **P-TEFb:** This complex is composed of two subunits, CDK9 and cyclin T1. It phosphorylates the C-terminal domain (CTD) of RNA polymerase II, leading to the recruitment of splicing factors and other downstream processing factors.

**Other factors associated with the elongation complex:**

* **FACT (Facilitates Chromatin Transcription):** This complex is comprised of two subunits, Spt16 and SSRP1. It helps to displace nucleosomes, allowing RNA polymerase II to access the DNA template.
* **Elongator complex:** This complex is composed of six subunits, including Elp1-Elp6. It contributes to transcriptional elongation by modifying histone H3.
* **Mediator complex:** This large multi-protein complex is involved in regulating transcription initiation and elongation. It interacts with both RNA polymerase II and specific transcription factors.

**Overall, the transcription elongation factor complex is a dynamic assembly that facilitates the efficient and accurate transcription of DNA into RNA. Its components work together to overcome obstacles, regulate elongation speed, and coordinate downstream RNA processing events.**'
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Proteins (1)

Compounds (282)