General transcription factors play a crucial role in the transcription process of all genes within the genome. These factors are essential for the recruitment of RNA polymerase to the promoter region of a gene, which is necessary for initiating transcription. The assembly of these components forms what is known as the transcription initiation complex (TIC), which includes all general transcription factors along with RNA polymerase.
In eukaryotic organisms, a specific DNA sequence known as the TATA box is vital for this process. The TATA box consists of repeating adenine (A) and thymine (T) nucleotides and is located within the promoter region. This sequence is responsible for attracting the TIC, thereby facilitating the binding of general transcription factors and RNA polymerase to the promoter.
When general transcription factors bind to the TATA box, they create a platform for RNA polymerase to attach, forming the transcription initiation complex. Once this complex is established, transcription can commence, allowing the coding sequence of the gene to be transcribed into RNA.
Understanding the function of general transcription factors and the TATA box is fundamental to grasping the mechanisms of transcriptional control. This knowledge sets the stage for further exploration of specific transcription factors, which will be discussed in subsequent lessons.