Pre Initiation Complex
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
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