Regulation of Transcription Flashcards
What happens during the Regulation of Transcription?
- A Transcription Factor protein binds to the operator
- RNA Pol binds to the promoter to begin transcription
Prokaryotes have general transcription factors, which are
A class of proteins that bind to specific sites on the DNA to activate transcription
What does the basic transcription apparatus consist of?
- General TFs
- RNA Pol
- Mediator Multiple Protein Complex
What is the function of the transcription apparatus?
It positions the RNA Pol right at the beginning of a protein coding sequence / gene and then releases Pol
What are Activators?
DNA Binding proteins which enhance interaction between RNA Pol and a particular promoter, encouraging expression of a gene
How do Activators increase the attraction of RNA Pol for the promoter?
They do so via interactions of RNA Pol or by changing structure of DNA
What is an example of an Activator protein?
CAP
What is the function of CAP?
It activates transcription of Lac Operon
What allows for CAP to bind to DNA + make interaction with RNA Pol?
cAMP binds to the CAP, causing for a conformational change
What are Enhancers?
Sites on the DNA bound to by activators
What is the function of Enhancers?
They allow for the looping of DNA to bring a specific promoter to the initiation complex
Enhancers enhance transcription of the gene and are usually
Cis-acting
Enhancers don’t act on the promoter region itself but are bound by
Activators which do most of the work
What are Repressors?
Proteins that bind to the operator and impede the RNA Pol
Repressors detach from the operator when
An inducer comes in
