MBB 222 Lecture Notes - Lecture 29: Tata-Binding Protein, Zinc Finger, Tata Box
20 Dec 2018
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Document Summary
Binding of rnap ii transcription factors to promoter, initiation of polymerization. Tfiid binds to the tata box via its tata binding protein, tbp, a 30 kda component of the large (700 kda) tfiid complex tbp is a saddle-shaped protein containing two similar domains (blue and green in figure) Tbp binds to the minor groove of the tata box via its concave surface. Binding induces a large conformational change in the dna, bending it and spreading the minor groove. Phe side chains of tbp intercalate between the base pairs of the minor groove the unique conformation of the tfiid and the kinked dna may provide a docking site for additional tfs and rnap ii. Bind to the major groove of dna. The amino acid sequences of each zinc fingers are very similar (i. e. , a tandem repeat ). (b) the -helices of each zinc finger interact with guanine bases in similar ways.
