1qpi

<table><tr><td colspan='2'>[[1qpi]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QPI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QPI FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IMD:IMIDAZOLE'>IMD</scene></td></tr>

[[https://www.uniprot.org/uniprot/TETR4_ECOLX TETR4_ECOLX]] TetR is the repressor of the tetracycline resistance element; its N-terminal region forms a helix-turn-helix structure and binds DNA. Binding of tetracycline to TetR reduces the repressor affinity for the tetracycline resistance gene (tetA) promoter operator sites.

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== Publication Abstract from PubMed ==

The tetracycline repressor (TetR) regulates the most abundant resistance mechanism against the antibiotic tetracycline in grain-negative bacteria. The TetR protein and its mutants are commonly used as control elements to regulate gene expression in higher eukaryotes. We present the crystal structure of the TetR homodimer in complex with its palindromic DNA operator at 2.5 A resolution. Comparison to the structure of TetR in complex with the inducer tetracycline-Mg2+ allows the mechanism of induction to be deduced. Inducer binding in the repressor core initiates conformational changes starting with C-terminal unwinding and shifting of the short helix a6 in each monomer. This forces a pendulum-like motion of helix a4, which increases the separation of the attached DNA binding domains by 3 A, abolishing the affinity of TetR for its operator DNA.

Structural basis of gene regulation by the tetracycline inducible Tet repressor-operator system.,Orth P, Schnappinger D, Hillen W, Saenger W, Hinrichs W Nat Struct Biol. 2000 Mar;7(3):215-9. PMID:10700280<ref>PMID:10700280</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1qpi" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Bacillus coli migula 1895]]

[[Category: Hillen, W]]

[[Category: Hinrichs, W]]

[[Category: Orth, P]]

[[Category: Saenger, W]]

[[Category: Schnappinger, D]]

[[Category: Transcription-dna complex]]