Many factors bind around the core promoter to form the eukaryotic initation complex, but the most important one is ______, which directly binds the TATA box.

The TFIID is a key protein to the initiation of the transcription event. It initially recognizes the TATA box, which is a short double-helical DNA sequence composed of T's and A's nucleotides. The TATA box is not only a DNA sequence that signals the start of transcription, but for most polymerase II promoters it is the most important. The other role for the TFIID is to recognize other DNA sequences near the transcription start point and this is possible by a large distortion in the DNA of the TATA box. The distortion seems to be a physical landmark that promotes the assembly of the transcription initiation complex along with the RNA polymerase II.