RNA polymerase II transcription regulator complex

Definition

Target type: cellularcomponent

A transcription factor complex that acts at a regulatory region of a gene transcribed by RNA polymerase II. [GOC:tb]

The RNA polymerase II (RNAP II) transcription regulator complex is a multi-protein assembly that plays a crucial role in gene expression. It is responsible for transcribing protein-coding genes from DNA into messenger RNA (mRNA), which subsequently serves as a template for protein synthesis. This complex consists of a core polymerase, which catalyzes the synthesis of RNA, and numerous accessory factors that regulate its activity and specificity. The core polymerase is composed of 12 subunits, which can be grouped into four major functional domains: the core enzyme, the clamp, the bridge helix, and the RNA exit channel. The core enzyme contains the catalytic site for RNA synthesis, while the clamp helps to maintain the stability of the complex and its interaction with DNA. The bridge helix is involved in the transition from initiation to elongation of transcription, and the RNA exit channel facilitates the passage of the newly synthesized RNA from the polymerase. In addition to the core polymerase, the RNAP II transcription regulator complex includes a diverse set of accessory factors. These factors can be broadly categorized into general transcription factors (GTFs) and transcription co-regulators. GTFs are essential for the initiation of transcription and include factors like TFIIB, TFIID, TFIIE, TFIIF, and TFIIH. These factors interact with the core polymerase, DNA, and each other to assemble the pre-initiation complex (PIC), which is the foundation for transcription. Transcription co-regulators are proteins that modulate the activity of the RNAP II transcription regulator complex, either positively or negatively. These factors can be broadly categorized into activators and repressors. Activators stimulate transcription by interacting with the core polymerase or GTFs, while repressors inhibit transcription by blocking the assembly or function of the PIC. The RNAP II transcription regulator complex is highly dynamic and can undergo significant conformational changes during the transcription cycle. These changes are essential for regulating the initiation, elongation, and termination of transcription. The complex is also subject to numerous post-translational modifications, such as phosphorylation, acetylation, and methylation, which further modulate its activity and specificity. In summary, the RNAP II transcription regulator complex is a highly complex and dynamic molecular machine that plays a central role in gene expression. It is composed of a core polymerase and numerous accessory factors that work together to ensure the accurate and efficient transcription of protein-coding genes.'
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Proteins (32)

Compounds (614)