iBet uBet web content aggregator. Adding the entire web to your favor.
iBet uBet web content aggregator. Adding the entire web to your favor.



Link to original content: http://pubmed.ncbi.nlm.nih.gov/21261817/
The application of Tet repressor in prokaryotic gene regulation and expression - PubMed Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2008 Jan;1(1):2-16.
doi: 10.1111/j.1751-7915.2007.00001.x.

The application of Tet repressor in prokaryotic gene regulation and expression

Ralph Bertram  1 , Wolfgang Hillen
Affiliations
Review

The application of Tet repressor in prokaryotic gene regulation and expression

Ralph Bertram et al. Microb Biotechnol. 2008 Jan.

Abstract

Inducible gene expression based upon Tet repressor (tet regulation) is a broadly applied tool in molecular genetics. In its original environment, Tet repressor (TetR) negatively controls tetracycline (tc) resistance in bacteria. In the presence of tc, TetR is induced and detaches from its cognate DNA sequence tetO, so that a tc antiporter protein is expressed. In this article, we provide a comprehensive overview about tet regulation in bacteria and illustrate the parameters of different regulatory architectures. While some of these set-ups rely on natural tet-control regions like those found on transposon Tn10, highly efficient variations of this system have recently been adapted to different Gram-negative and Gram-positive bacteria. Novel tet-controllable artificial or hybrid promoters were employed for target gene expression. They are controlled by regulators expressed at different levels either in a constitutive or in an autoregulated manner. The resulting tet systems have been used for various purposes. We discuss integrative elements vested with tc-sensitive promoters, as well as tet regulation in Gram-negative and Gram-positive bacteria for analytical purposes and for protein overproduction. Also the use of TetR as an in vivo biosensor for tetracyclines or as a regulatory device in synthetic biology constructs is outlined. Technical specifications underlying different regulatory set-ups are highlighted, and finally recent developments concerning variations of TetR are presented, which may expand the use of prokaryotic tet systems in the future.

PubMed Disclaimer

Figures

Figure 1
Figure 1
A. Structure of the TetR–tetO complex as determined by Orth and colleagues (2000). TetR is depicted in a ribbon representation with one monomer coloured grey and the other coloured blue. The numbers of helices are given in the blue monomer. Note that the linker sequence between helices α8 and α9 of both monomers is not resolved. The bound DNA is depicted as a ball‐and‐stick model.
B. Structure of TetR in the tc‐bound form according to Hinrichs and colleagues (1994). Representations are as in (A). Tetracycline is given as orange spheres, with two molecules bound to the two inducer‐binding pockets of TetR.
Figure 2
Figure 2
Sequence of the tetR–tetA intergenic region of Tn10 according to Chalmers and colleagues (2000). The three promoters are depicted as thin arrows with the –35 and the –10 regions symbolized by black boxes. The arrow tips mark the transcription start points. Squares indicate tetO sequences, and the black or grey filled arrows indicate the start codons of tetR or tetA respectively.
Figure 3
Figure 3
Different architectures of tet‐regulation system are shown. Depicted are tetR (black arrow) and the target gene (grey arrow), controlled by a tc‐sensitive promoter (grey bent arrow with grey box symbolizing tetO). Situations are: (A) target gene and tetR on one plasmid; (B) target gene and tetR on two distinct plasmids; (C) target gene and tetR on chromosome; (D) target gene on plasmid, tetR on chromosome; (E) target gene and tetR on chromosome, adjacent; (F) target gene and tetR on chromosome, distinct loci. Remarks: Several studies applied more than one architecture. The articles by Pósfai and colleagues (1994; 1997; 1999) describe the use of plasmids which were subsequently integrated into the genome. Possoz and colleagues (2006) applied a plasmid expressing TetR for non‐transcriptional regulation. Bae and Schneewind (2006) used tet regulation to counterselect for the episomal state of the DNA. In contrast to the drawing in the head of the figure, Rodriguez‐Garcia and colleagues (2005) placed tetR collinear to, and hence uncoupled from, the target gene, which is also true for the construct of Skerra (1994) and derivatives thereof. The tet‐regulation vector developed by Woo and colleagues (2005) has only approximately one copy per Laribacter cell.
Figure 4
Figure 4
Representation of selected promoters for tetregulation. The architecture is schematically depicted and not drawn to scale. –35 and –10 denote the respective base‐pair hexamers of the promoters. ‘O’ designates tet operator. The indicated approximated induction factors (IF) were achieved under circumstances briefly outlined at the right side. n.d., not determined.
Figure 5
Figure 5
A. Depiction of tetO2 and two derived operator variants with single‐base‐pair exchanges in each half‐side.
B. Chemical structure of tc (with key carbon atoms numbered), atc and 4‐de‐dimethylamino‐atc.
C. Regulation principle of wt‐TetR (top) and revTetR (bottom). wt‐TetR is depicted with black ovals representing the protein core and grey ovals symbolizing DNA reading heads. revTetR is depicted accordingly with hatched fillings. A tet controlled target gene is repressed (grey arrow) or induced (white arrow), dependent on the absence or presence of effector molecules (white triangles) bound to TetR.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Agerso Y., Guardabassi L. Identification of Tet 39, a novel class of tetracycline resistance determinant in Acinetobacter spp. of environmental and clinical origin. J Antimicrob Chemother. 2005;55:566–569. - PubMed
    1. Bae T., Schneewind O. Allelic replacement in Staphylococcus aureus with inducible counter‐selection. Plasmid. 2006;55:58–63. - PubMed
    1. Bahl M.I., Hansen L.H., Licht T.R., Sorensen S.J. In vivo detection and quantification of tetracycline by use of a whole‐cell biosensor in the rat intestine. Antimicrob Agents Chemother. 2004;48:1112–1117. - PMC - PubMed
    1. Bahl M.I., Hansen L.H., Sorensen S.J. Construction of an extended range whole‐cell tetracycline biosensor by use of the tet(M) resistance gene. FEMS Microbiol Lett. 2005;253:201–205. - PubMed
    1. Batchelor E., Silhavy T.J., Goulian M. Continuous control in bacterial regulatory circuits. J Bacteriol. 2004;186:7618–7625. - PMC - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources