Users' questions

Does pGEX have T7 promoter?

Does pGEX have T7 promoter?


What is T7 promoter sequence?

What Is the T7 Promoter Sequence? The T7 promoter is a sequence of DNA 18 base pairs long up to transcription start site at +1 (5′ – TAATACGACTCACTATAG – 3′) that is recognized by T7 RNA polymerase1 .

What induces T7 promoter?

Upon heat induction, the T7 RNA polymerase is produced and initiates transcription on the expression vector, resulting in turn in the expression of the gene(s) under the control of p(T7).

Why can the E coli RNA polymerase not transcribe the pET vector?

Protein Expression in Bacteria coli RNA polymerase, and therefore virtually no expression occurs until a source of T7 RNA polymerase is provided. Genes cloned in pET vectors are virtually “off” and cannot cause plasmid instability due to the production of proteins potentially toxic to the host cell.

How does the T7 promoter support bacterial expression?

Both the T7 and Champion™ pET expression vectors contain a strong bacteriophage T7 promoter. After induction with IPTG, T7 RNA polymerase will bind the T7 promoter, leading to transcription and translation of your gene of interest.

What is the promoter sequence of the pGem-T vector?

The promoter and multiple cloning sequence of the pGEM®-T (Panel A) and pGEM®-T Easy (Panel B) Vectors.The top strand of the sequence shown corresponds to the RNA synthesized by T7 RNA Polymerase.The bottom strand corresponds to the RNA synthe- sized by SP6 RNA Polymerase.

Is the PTRC promoter recognized by T7 polymerase?

The pTrc promoter is recognized by E. coli RNA polymerase, not T7 polymerase, and therefore can be expressed in any E. coli strain, not just BL21 strains. Therefore, you can use Top10, DH5α™, etc. for expression. However, if your gene is toxic, the cloning step can be difficult as there is leakiness in expression.

Which is T7 polymerase transcribes only DNA downstream of the promoter?

T7 polymerase is extremely promoter-specific and transcribes only DNA downstream of a T7 promoter (TAATACGACTCACTATAG, transcription beginning with the 3′ G). The T7 polymerase also requires a double stranded DNA template and Mg2+ ion as cofactor for the synthesis of RNA.