TOPIC 1 Principles of Transcriptional Regulation [watch the animation TOPIC 2 Regulation of Transcription Initiation: Examples from Bacteria Lac operon, alternative o factors NtrC, MerR, Gal rep, araBAD operon) TOPIC 3 Examples of Gene Regulation after Transcription Initiation (Trp operon TOPIC 4 The Case of phage a Layers of Regulation
11 TOPIC 1 Principles of Transcriptional Regulation [watch the animation] TOPIC 2 Regulation of Transcription Initiation: Examples from Bacteria (Lac operon, alternative s factors, NtrC,MerR, Gal rep, araBAD operon) TOPIC 3 Examples of Gene Regulation after Transcription Initiation (Trp operon) TOPIC 4 The Case of Phage λ: Layers of Regulation
CHAPTER 16 Gene Regulation in Prokaryotes Topic 1: Principles of Transcription Regulation 5/10/2005 @博共字 Wuhan Universit
12 Topic 1: Principles of Transcription Regulation CHAPTER 16 Gene Regulation in Prokaryotes 5/10/2005
1-1 Gene Expression is Controlled t'y Regulatory Proteins S Gene expression is very often controlled by Extracellular Signals, which are communicated to genes by regulatory proteins Positive requlators or activators INCREASE the transcription Negative requlators or repressors dECReaSE or ELIMINaTE the transcription 13
13 1-1 Gene Expression is Controlled by Regulatory Proteins Gene expression is very often controlled by Extracellular Signals, which are communicated to genes by regulatory proteins : ➢ Positive regulators or activators INCREASE the transcription ➢ Negative regulators or repressors DECREASE or ELIMINATE the transcription Principles of Transcription Regulation
What are the transcription steps targeted by the requlators 14
14 What are the transcription steps targeted by the regulators ?
RNA polymerase Fig 12-3-initiation upstream downstream DNA DNA promoter Promoter Binding binding (closed complex) (closed complex promoter maltin Promoter“ melting (ope complex (open complex) initial Initial RNA transcription
15 Fig 12-3-initiation Promoter Binding (closed complex) Promoter “melting” (open complex) Initial transcription