Chapter 20 Initiation of transcription 莘大
Chapter 20 Initiation of transcription
20.1 Introduction 20.2 Eukaryotic RNA polymerases consist of many subunits 20.3 Promoter elements are defined by mutations and footprinting 20.4RNA polymerase I has a bipartite promoter 20.5 RNA polymerase Ill uses both downstream and upstream promoters 20.6 The startpoint for rna polymerase ll 20. 7TBPis a universal factor 20.8 TBP binds DNAin an unusual way 20.9 The basal apparatus assembles at the promoter 20.10 Initiation is followed by promoter clearance 20.11 Aconnection between transcription and repair 20.12 Promoters for RNa polymerase ll have short sequence elements 20.13 Some promoter-binding proteins are repressors 20.14 Enhancers contain bidirectional elements that assist initiation 20.15 Independent domains bind DNA and activate transcription 20.16 The two hybrid assay detects protein-protein interactions 20. 17 Interaction of upstream factors with the basal apparatus 消当
20.1 Introduction 20.2 Eukaryotic RNA polymerases consist of many subunits 20.3 Promoter elements are defined by mutations and footprinting 20.4 RNA polymerase I has a bipartite promoter 20.5 RNA polymerase III uses both downstream and upstream promoters 20.6 The startpoint for RNA polymerase II 20.7 TBP is a universal factor 20.8 TBP binds DNA in an unusual way 20.9 The basal apparatus assembles at the promoter 20.10 Initiation is followed by promoter clearance 20.11 A connection between transcription and repair 20.12 Promoters for RNA polymerase II have short sequence elements 20.13 Some promoter-binding proteins are repressors 20.14 Enhancers contain bidirectional elements that assist initiation 20.15 Independent domains bind DNA and activate transcription 20.16 The two hybrid assay detects protein-protein interactions 20.17 Interaction of upstream factors with the basal apparatus
20.1Introduction Enhancer element is a cis-acting sequence that increases the utilization of (some)eukaryotic promoters, and can function in either orientation and in any location (upstream or downstream relative to the promoter 消当
Enhancer element is a cis-acting sequence that increases the utilization of (some) eukaryotic promoters, and can function in either orientation and in any location (upstream or downstream) relative to the promoter. 20.1 Introduction
20. 1Introduction Enhancer Prom oter Gene 100b 200 bp up stream of startpoint Contains several Separation of Contains dispersed sequence elem ents dosely arranged enhancer from that bind transcription factors se quence promoter at element s that bind be several kb Only the elem ents in the imm ediate transcription vicinity(200 bp. An enhancer containing a more closely packed array of elements that also bind transcription factors may be located several kb distant (DNA may be coiled or otherwise rearranged so that transcription factors at the promoter 请莘大 and at the enhancer interact to form a large protein complex
Figure 20.1 A typical gene transcribed by RNA polymerase II has a promoter that extends upstream from the site where transcription is initiated. The promoter contains several short (200 bp. An enhancer containing a more closely packed array of elements that also bind transcription factors may be located several kb distant. (DNA may be coiled or otherwise rearranged so that transcription factors at the promoter and at the enhancer interact to form a large protein complex.) 20.1 Introduction
20.2 Eukaryotic RNA polymerases consist of many subunits Amanitin(more fully a-amanitin)is a bicyclic octapeptide derived from the poisonous mushroom amanita halloides; it inhibits transcription by certain eukaryotic rNa polymerases especially rna polymerase II 请莘大
Amanitin (more fully a-amanitin)is a bicyclic octapeptide derived from the poisonous mushroom Amanita phalloides; it inhibits transcription by certain eukaryotic RNA polymerases, especially RNA polymerase II. 20.2 Eukaryotic RNA polymerases consist of many subunits
20.2 Eukaryotic RNA polymerases consist of many subunits Size No Features 1 Related to bacterial subunit Br 20 binds dna has CTD =(YSPTSPS) least n=26: mouse n=52 1 Related to bacterial subunit B 10u binds nucleotides Figure 20.2 2 Related to bacterial subunit ox. Eukaryotic RNa 10 subunits Common to all 3 polymerases 消当
Figure 20.2 Eukaryotic RNA polymerase II has >10 subunits. 20.2 Eukaryotic RNA polymerases consist of many subunits
20.3 Promoter elements are defined by mutations and footprinting Cotransfection is the simultaneous transfection of two markers 消当
Cotransfection is the simultaneous transfection of two markers. 20.3 Promoter elements are defined by mutations and footprinting
Upstream Promoter Transcribed region 20.3 Promoter 八A elements are defined NA by mutations and Delete and reconnect footprinting Transcription Figure 20.3 Promoter boundaries can be determined by making deletions that progressively RNA still made deletion does not enter promote remove more material from one side. When one deletion fails to Delete and reconnect prevent RNa synthesis but the next stops transcription. the boundary of the promoter must lie between them No RNA made deletion has entered promoter 消当 Upstream boundary of pro between ends of deletions
Figure 20.3 Promoter boundaries can be determined by making deletions that progressively remove more material from one side. When one deletion fails to prevent RNA synthesis but the next stops transcription, the boundary of the promoter must lie between them. 20.3 Promoter elements are defined by mutations and footprinting
Pol I prom oters have two sequence components 20, RNA CTCCGAGTCGNNNNNNTGGGC Startpoint polymerase I has a Upstream control element Core prom oter 170-160-150140-130-120-110 -605040 +10+20 bipartite promoter 人AAA The initiation complex assembles in three stages Figure 20.4 Transcription units UBF UBFI binds to G-C-nich sequence for RNa polymerase I have a cp r oro mhe ep stream ontrol Av element. UBFl binds to both SL SL1 binds cooperati ath UBF 1 regions. after which SLl can bind RNA polymerase I then binds to the core promoter. The 八 AVMVVN nature of the interaction between the factors bound at the 题 upstream controlelement and those at the core promoter is not VVALv known 消当
Figure 20.4 Transcription units for RNA polymerase I have a core promoter separated by ~70 bp from the upstream control element. UBF1 binds to both regions, after which SL1 can bind. RNA polymerase I then binds to the core promoter. The nature of the interaction between the factors bound at the upstream control element and those at the core promoter is not known. 20.4 RNA polymerase I has a bipartite promoter
20.5RNA polymerase Ill uses both downstream and upstream promoters Preinitiation complex in eukaryotic transcription describes the assembly of transcription factors at the promoter before rna polymerase binds 消当
Preinitiation complex in eukaryotic transcription describes the assembly of transcription factors at the promoter before RNA polymerase binds. 20.5 RNA polymerase III uses both downstream and upstream promoters
