BIOL308 Lecture Notes - Lecture 16: Taf15, Xpb, Lac Operon
4 Feb 2015
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Document Summary
General transcription factors: general transcription factors are necessary for transcription in eukaryotes from all genes (all three. General (basal) transcription factors cont: tfiid is largest and consists of a tata box- binding protein (tbp) and tbp-associated factors (tafs; different # in different species) Tfiid has two basic roles: foundation for the transcriptional complex (tfiid - tbp has to be bound for transcription to start, prevention of the nucleosome stabilization (=nucleosome destabilization) in the promoter region (antagonist to h1) Weaver, 3rd edition: tbp is first protein to bind to tata box. Highly conserved with similar c terminal domains of 180 aa. Tafs tbp associated factors: determine whether or not tfiid stays at the promoter. Some promoters more difficult to transcribe from then the others: interaction with gene specific transcription factors, interact with co-activators (bridge with enhancer-bound proteins, contact initiator and downstream elements, role in looping. From: tora, l. genes dev. (2002) 16: 673-675. Tfiid binds tata box through binding of tbp.
