RNA聚合酶II启动转录需要70多种多肽的活性协调这些活动的蛋白质是转录因子iid（tfiid），它与核心启动子结合以正确定位聚合酶，充当组装其余转录复合物的支架，并充当调控信号的通道。TFIID由TATA结合蛋白（TBP）和一组进化上保守的蛋白质（TBP相关因子或taf）组成tafs可能参与基础转录，充当协同激活因子，在启动子识别中发挥作用，或修饰一般转录因子（gtfs），以促进复杂的组装和转录起始。这个基因编码TBP，TATA结合蛋白tbp的一个显著特征是n端有一长串谷氨酰胺。蛋白质的这一区域调节C末端的DNA结合活性，DNA结合的调节影响转录复合物的形成和转录起始的速度编码多聚谷氨酰胺通道的CAG重复的数目通常为25-42，重复到45-66的数目的增加增加了聚谷氨酰胺串的长度，并与脊髓小脑共济失调17相关，该神经退行性疾病被归类为多聚谷氨酰胺病。已经发现了两个编码不同亚型的转录变体。[由RefSeq提供，2016年7月]
Initiation of transcription by RNA polymerase II requires the activities of more than 70 polypeptides. The protein that coordinates these activities is transcription factor IID (TFIID), which binds to the core promoter to position the polymerase properly, serves as the scaffold for assembly of the remainder of the transcription complex, and acts as a channel for regulatory signals. TFIID is composed of the TATA-binding protein (TBP) and a group of evolutionarily conserved proteins known as TBP-associated factors or TAFs. TAFs may participate in basal transcription, serve as coactivators, function in promoter recognition or modify general transcription factors (GTFs) to facilitate complex assembly and transcription initiation. This gene encodes TBP, the TATA-binding protein. A distinctive feature of TBP is a long string of glutamines in the N-terminus. This region of the protein modulates the DNA binding activity of the C terminus, and modulation of DNA binding affects the rate of transcription complex formation and initiation of transcription. The number of CAG repeats encoding the polyglutamine tract is usually 25-42, and expansion of the number of repeats to 45-66 increases the length of the polyglutamine string and is associated with spinocerebellar ataxia 17, a neurodegenerative disorder classified as a polyglutamine disease. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2016]