What is AraC used for?

What is AraC used for?

The system has evolved to include two positive regulatory proteins (AraC + arabinose; CRP), one negative regulatory element (AraC – arabinose), a mechanism to control gene expression through DNA looping, and a system that can prevent or enhance an interaction with the RNA polymerase.

What is AraC gene?

Abstract. The araC gene encodes a positive regulatory protein required for L-arabinose utilization in Escherichia coli. Transcription from the araC promoter has been shown to be under positive control by cAMP receptor protein and under negative control by its protein product (autoregulation).

What is AraC in a plasmid?

araC — gene that encodes the regulatory protein that binds to the pBAD promoter; only when arabinose binds to the AraC protein is the production of GFP switched on.

What does AraC stand for in biology?

Cytarabine, (also known as cytosine arabinoside (ara-C)) a chemotherapeutic agent commonly used in the treatment of leukemias and lymphomas.

What happens to AraC in the absence of arabinose?

If arabinose is absent, the dimer AraC protein represses the structural gene by binding to araI1 and araO2 and the DNA forms a loop, which prevents RNA polymerase from binding to the promoter of the ara operon, thereby blocking transcription.

What is the function of pBAD?

The pBAD expression system allows tightly controlled, titratable expression of your protein through the regulation of specific carbon sources such as glucose, glycerol, and arabinose. pBAD is ideal for expressing toxic proteins and optimizing protein solubility in E. coli.

How does the AraC operon work?

The ara operon is regulated by the AraC protein. If arabinose is absent, the dimer AraC protein represses the structural gene by binding to araI1 and araO2 and the DNA forms a loop, which prevents RNA polymerase from binding to the promoter of the ara operon, thereby blocking transcription.

Is AraC a promoter?

Both araC and araBAD have a discrete promoter where RNA polymerase binds and initiates transcription.

How does the AraC regulatory protein turn on transcription in the presence of arabinose?

In the presence of arabinose, AraC binds to two adjacent sites and activates transcription by functioning as a Class II activator. In the absence of arabinose, the activating AraC molecule shifts to bind at a distal site, resulting in loop formation that represses transcription.

Is AraC an activator?

AraC acts as an activator in the presence of arabinose. AraC undergoes a conformational change when arabinose binds to the dimerization domain of AraC.

What happens to the AraC protein when arabinose is present?

When arabinose is present, arabinose binds AraC and prevents it from interacting. This breaks the DNA loop. The two AraC-arabinose complexes bind to the araI site which promotes transcription.

How do you induce pBAD?

While using pBAD promoter for protein purification, we use 0.1% arabinose for induction. You can induce at lower O.D. as well, we induce at O.D. of 0.1, and this works for everyone in our lab.