BIOSC-101 Lecture Notes - Lecture 9: Cytosol, Post-Translational Modification, Transcription Preinitiation Complex
26 Aug 2020
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2 to regulate assembly of the preiniatior complex. For transcription to occur w eukaryotes one must have. Activators attract, position, and modify tf"s as well as pol 2 at the start of transcription. Activators interact with mediator of transcription complex that binds to pol. May require chromatin modifying enzymes (chromatin remodeling complexes and histone acetyuses) to increase accessibility of dna. Repressors block assembly of general tf"s from interacting w the dna. Reva polymerase are associated with elongation factors (prevent polymerase from dissociating with dna before it reaches stop site, and help it traverse through more compacted regions of chromatin) during elongation. Tf"s can inhibit elongation or releases elongation inhibitors. Repressors can compete with activators for dna binding sites or bind to the activation domain of activators to inhibit them. Example: please look at control of gene expression in yeast. Chromatin remodeling complex: multi-protein structure required for assembly of the transcription machinery at promoter site.
