"

From 2010.igem.org

Guys! Check this out!

• http://en.wikipedia.org/wiki/Tetracycline_controlled_transcriptional_activation

It's about tetR and Doxycycline

• http://en.wikipedia.org/wiki/Doxycycline

this one's about Doxycycline and its structure

tet: http://upload.wikimedia.org/wikipedia/commons/thumb/8/8e/Tetracycline_structure.svg/220px-Tetracycline_structure.svg.png dox: http://upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Doxycycline_Structural_Formulae.png/200px-Doxycycline_Structural_Formulae.png

• OOOOoooo check this out too!

http://parts.mit.edu/igem07/index.php/Caltech/Project/Constructs

It's another wiki page and has some info on tetR-controlled activation

The figure below illustrates the expected behavior of the final construct system in E. coli bacteria. A constitutive promoter (both J23100 and J23116) continuously produces transcripts of the tet repressor gene, which when translated turns into tet repressor protein (tetR). The pTet promoter drives expression of the desired protein, N/Q/cro or YFP. In the absence of aTc, the tetR binds to pTet, greatly reducing the number of protein transcripts (and thus the protein concentration) in the cell. Adding aTc increases the protein concentration, as aTc binds to tetR and frees the pTet promoter to produce more transcripts. The pTet system allows us to reach intermediate expression levels, rather than switching between 'on' and 'off' states.

http://parts.mit.edu/igem07/images/0/0c/ConstructExplanation.png

Construct Behavior: With no aTc in the system, tetR represses pTet promoter activity, resulting in a small number of the “protein” in the cell. With the addition of a saturating concentration of aTc, all the tetR protein is bound, leaving the pTet promoter free to produce the viral proteins that will lead viruses towards the lytic pathway.

• TetR structure

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1197418/bin/zmr0020520860002.jpg

tetR-controlled activation regulation

• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1197418/

When TetR binds to tetR operator, it makes the promoter attached to operator work
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1197418/bin/zmr0020520860003.jpg
Binding of TetR to its operator site. A) tetR operator and contact regions. The tetR operator is a palindromic sequence. Horizontal bars show nucleotides contacted by each monomer of the TetR dimer. B) Interaction of TetR residues with specific nucleotides (arrows) and phosphate backbone (blue lines) in the operator region. The amino acids involved in DNA binding extend from residues 27 to 48. Contacts established with the operator were confirmed by footprint assays, by analysis of TetR mutants, and by crystallographic studies (29, 30, 159, 266, 366). C) Representation of each homodimer bound to the tet operator in a double-helix representation. (Adapted from Orth et al. [288] with permission of the publisher.)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1197418/bin/zmr002052086008a.jpg

--Needks 14:35, 4 September 2010 (UTC)