Zhao Xuemei, Herr Winship
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Cell. 2002 Mar 8;108(5):615-27. doi: 10.1016/s0092-8674(02)00648-7.
The TATA box binding protein TBP plays a universally important role in eukaryotic nuclear transcription. By mutagenesis, we have discovered a solvent-exposed surface of the structured TBP core domain that is important for inhibition of the DNA binding and DNA-bending activities of full-length wild-type TBP. Full-length wild-type TBP initially binds the TATA box to form an unstable complex containing unbent DNA, and then it slowly forms a stable complex containing bent DNA. TFIIB greatly accelerates formation of a bent TFIIB-TBP-TATA box complex, and the inhibitory DNA binding surface of TBP contributes to the cooperativity of binding to TFIIB. Using TBP and TFIIB, we show that TBP can bind the TATA box through a regulated two-step mechanism, involving a transition from unbent complex to bent complex.
TATA 框结合蛋白TBP在真核细胞核转录中发挥着普遍重要的作用。通过诱变，我们发现了结构化TBP核心结构域的一个溶剂暴露表面，该表面对于抑制全长野生型TBP的DNA结合和DNA弯曲活性很重要。全长野生型TBP最初结合TATA框形成一个包含未弯曲DNA的不稳定复合物，然后它缓慢形成一个包含弯曲DNA的稳定复合物。TFIIB极大地加速了弯曲的TFIIB-TBP-TATA框复合物的形成，并且TBP的抑制性DNA结合表面有助于与TFIIB结合的协同性。使用TBP和TFIIB，我们表明TBP可以通过一种受调控的两步机制结合TATA框，该机制涉及从未弯曲复合物到弯曲复合物的转变。
