| Modification Notes |
In eukaryotic systems, the process of initiating transcription from protein-coding genes requires the presence of RNA polymerase II and a broad family of auxiliary transcription factors. Such factors can be divided into two major functional classes: the basal factors that mediate the transcription of all Pol II genes, including TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH, and sequence-specific factors that regulate gene expression. TFIID, one of the basal transcription factors, facilitates the preinitiation complex assembly through direct interactions with the TATA promoter element. TAF9B (transcription initiation factor TFIID subunit 9B), also known as TAF9L, is similar to TAF9 and is a component of the TFIID complex. Essential for cell viability, TAF9B is involved in transcriptional activation through its N-terminal association with TP53/p53, a protein essential for transcription. TAF9B is ubiquitously expressed and is localized to the nucleus. TAF9 (transcription initiation factor TFIID subunit 9), also known as TAF9A or TAF II p32, is a 264 amino acid nuclear protein that, like TAF9B, is a component of the TFIID complex and is required for cell viability. |