Pre Initiation Complex: Difference between revisions
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== Pre Initiation Complex (PIC)<br> == | == Pre Initiation Complex (PIC)<br> == | ||
In [[Eukaryotes|eukaryotic]] [[Gene|gene]] expression the Pre Initiation Complex (PIC) mediates the binding between the [[Genome|genome]]'s promoter and [[RNA polymerase|RNA polymerase]]. Each type of RNA polymerase has a different PIC<ref>Cassimeris,L. et al, 2007 | In [[Eukaryotes|eukaryotic]] [[Gene|gene]] expression the Pre Initiation Complex (PIC) mediates the binding between the [[Genome|genome]]'s promoter and [[RNA polymerase|RNA polymerase]]. Each type of RNA polymerase has a different PIC<ref>Cassimeris,L. et al., 2007; p219 Lewin's cells. 2nd ed. Sudbury: Jones and Bartlett.</ref><br> | ||
== Subunits<br> == | == Subunits<br> == | ||
The complexicity of PIC varies between the types of eukaryotic [[ | The complexicity of PIC varies between the types of eukaryotic [[Rna polymerases in eukaryotes|RNA polymerase]]. For [[DNA polymerase I|polymerases I]] and [[Polymerase III|III]] the complex consists of only a few subunits.<br> | ||
For polymerase II the PIC is far more complex. It consists of 6 General Transcription Factors (GTF). TFIID is the core recognition [[Protein|protein]] and binds to the [[Tata box|TATA box]]. TFIIA stabilizes the binding complex. TFIID intreacts with TFIIB which brings in the RNA polymerase II which has TFIIF attached to it. This allows TFIIE and finally TFIIH to bind. TFIIH has [[ | For polymerase II the PIC is far more complex. It consists of 6 General Transcription Factors (GTF). TFIID is the core recognition [[Protein|protein]] and binds to the [[Tata box|TATA box]]. TFIIA stabilizes the binding complex. TFIID intreacts with TFIIB which brings in the RNA polymerase II which has TFIIF attached to it. This allows TFIIE and finally TFIIH to bind. TFIIH has [[Helicase|helicase]] activity and starts seperating the strands at the [[Open complex|Open Complex]]. Further it has CTD [[Kinase|Kinase activity]] and facilitates [[DNA]] repair. <br> | ||
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Revision as of 19:21, 20 November 2011
Pre Initiation Complex (PIC)
In eukaryotic gene expression the Pre Initiation Complex (PIC) mediates the binding between the genome's promoter and RNA polymerase. Each type of RNA polymerase has a different PIC[1]
Subunits
The complexicity of PIC varies between the types of eukaryotic RNA polymerase. For polymerases I and III the complex consists of only a few subunits.
For polymerase II the PIC is far more complex. It consists of 6 General Transcription Factors (GTF). TFIID is the core recognition protein and binds to the TATA box. TFIIA stabilizes the binding complex. TFIID intreacts with TFIIB which brings in the RNA polymerase II which has TFIIF attached to it. This allows TFIIE and finally TFIIH to bind. TFIIH has helicase activity and starts seperating the strands at the Open Complex. Further it has CTD Kinase activity and facilitates DNA repair.
- ↑ Cassimeris,L. et al., 2007; p219 Lewin's cells. 2nd ed. Sudbury: Jones and Bartlett.