Each fold composing the araC dimer is shown in blue and green ribbons, while the bound alpha-L-arabinose is shown in balls and stick format. Link to pdbsum : informations regarding the A-fold of the dimer AraC. The Arabinose Operon . What are some different operons , and how they work. The arabinose binding protein, one of many transport proteins in E. coli. PBAD Vectors use the AraC gene of the arabinose operon to help regulate the pBad promoter. When arabinose binds to the AraC molecule, it induces the pBAD promoter, and significantly increases its level of activity. It is also susceptible to catabolite repression when glucose is present, and the level of cAMP rises in the medium. Several operons are also susceptible to this catabolite repression, as shown here. What motivated my choice of protein is the system I have used to provide an S17-1 E. coli strain with a poison-antidote, programed death system: parD and parE in trans. To do so, I had placed the parD gene encoding for the anti-poison under the control of a pBADpromoter, in the pBAD24 vector. The toxin encoded by parE is provided by a pBBR1 plasmid, under the control of pLac promoter. As we have seen, both these promoters can have their level of expression greatly reduced by addition of glucose in the growth medium, and each promoter is induced by a different type of sugar (lactose or arabinose). This will allow a fine control over the level of expression of each gene, and directly view the consequences of high levels of either of those proteins. The result is a good level of survival when parD is induced through the presence of arabinose in the medium while parE is not, due to the absence of lactose able to bind to the lacY repressor made by the S17-1, lac+ strain. The reverse is also true, and we observe a 99.9% killing rate when lactose is added to the medium instead of arabinose, thus inducing the pLac by binding to the lacY repressor, thus releasing it from the DNA. This will increase the production of the parE toxin while pBAD is repressed. L-Arabinose-Binding Protein This monomer binds the arabinose in its center, and serves as transport protein in E. coli. Yu Tzi-Sin Bernard IRBIO-5 ULB June 5th 1999.
Each fold composing the araC dimer is shown in blue and green ribbons, while the bound alpha-L-arabinose is shown in balls and stick format.
Link to pdbsum : informations regarding the A-fold of the dimer AraC.
The Arabinose Operon . What are some different operons , and how they work. The arabinose binding protein, one of many transport proteins in E. coli.
PBAD Vectors use the AraC gene of the arabinose operon to help regulate the pBad promoter. When arabinose binds to the AraC molecule, it induces the pBAD promoter, and significantly increases its level of activity. It is also susceptible to catabolite repression when glucose is present, and the level of cAMP rises in the medium. Several operons are also susceptible to this catabolite repression, as shown here.
What motivated my choice of protein is the system I have used to provide an S17-1 E. coli strain with a poison-antidote, programed death system: parD and parE in trans.
To do so, I had placed the parD gene encoding for the anti-poison under the control of a pBADpromoter, in the pBAD24 vector. The toxin encoded by parE is provided by a pBBR1 plasmid, under the control of pLac promoter.
As we have seen, both these promoters can have their level of expression greatly reduced by addition of glucose in the growth medium, and each promoter is induced by a different type of sugar (lactose or arabinose). This will allow a fine control over the level of expression of each gene, and directly view the consequences of high levels of either of those proteins.
The result is a good level of survival when parD is induced through the presence of arabinose in the medium while parE is not, due to the absence of lactose able to bind to the lacY repressor made by the S17-1, lac+ strain. The reverse is also true, and we observe a 99.9% killing rate when lactose is added to the medium instead of arabinose, thus inducing the pLac by binding to the lacY repressor, thus releasing it from the DNA. This will increase the production of the parE toxin while pBAD is repressed.
L-Arabinose-Binding Protein This monomer binds the arabinose in its center, and serves as transport protein in E. coli. Yu Tzi-Sin Bernard IRBIO-5 ULB June 5th 1999.
