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Tet expression system

Features and benefits of the pASG-IBA vectors:

  • High-level expression in E. coli
  • Tightly regulated expression due to the tetracycline promoter
  • Enhanced stability of cytotoxic genes
  • Universal cloning strategy with one restriction enzyme
  • Inexpensive induction with anhydrotetracycline

The pASG-IBA vectors are available with Strep-tag®II, Twin-Strep-tag®, 6xHis-tag, GST-tag, Flag-tag®.

Principle and properties

pASG-IBA vectors work with the tightly regulated tetracycline (tet) promoter. Expression of the foreign gene is stringently repressed until induction with a low concentration of the chemical anhydrotetracycline. In contrast to the lac promoter, the tetA promoter/operator is tightly controlled and not functionally coupled to any cellular regulation mechanisms or genetic background. Unlike with the T7 promoter, special E. coli strains or extra plasmids are not required. The vectors do not mediate resistance against tetracycline.

 

T7 expression system

Features and benefits of the pPSG-IBA vectors

  • High-level expression by bacteriophage T7 promoter with pPSG-IBA vectors
  • High-level transcription by T7 RNA polymerase in BL21 strains
  • High-level expression of non-toxic proteins
  • Induction by IPTG
  • Universal cloning strategy with one restriction enzyme
  • Suitable for in vitro transcription/translation

The pPSG-IBA vectors are also available with Twin-Strep-tag, 6xHis-tag, GST-tag, Flag-tag or with two tags.

Principle and properties

The pPSG-IBA expression vectors are based on the T7 expression system. This system uses the T7 promoter and T7 RNA polymerase for high-level transcription of the gene of interest. Expression of the target genes is induced by providing a source of T7 RNA polymerase gene. The latter is under control of the lacUV5 promoter which can be induced by IPTG.

The advantage over the tet expression system is that this promoter is even stronger. The Tet promoter is of medium strength which leads to high level expression of certain proteins depending e.g. on their folding rate and stability – characteristics which can hardly be predicted. Some proteins, however, can only be expressed at high level if transcribed by a stronger promoter. In such cases we recommend the use of the T7 promoter.

Expression Vectors with Special Protease Cleavage Sites or Chloramphenical Resistance

Expression Vectors with Special Protease Cleavage Sites or Chloramphenical Resistance