Disease relevance of tetR

• In this study the cat and tetR genes were modified to either destroy complementarity to E. coli 16S RNA or completely delete their 5' non-translated regions [1].
• Crystal structure of the TetR/CamR family repressor Mycobacterium tuberculosis EthR implicated in ethionamide resistance [2].
• Differences between the experimental spectrum of the TetR:operator DNA complex and the computed sum of the component spectra provide direct spectroscopic evidence for changes in DNA backbone torsions and base stacking, rearrangement of protein backbone, and specific contacts between TetR residues and DNA bases [3].
• In Gram-positive bacteria genes for homologs of DhaK and DhaL occur in operons for putative transcription factors of the TetR and DeoR families [4].
• Inactivation of the target gene by IS10 insertion was detected by the expression of the tet gene from the phage 434 PR promoter, followed by Southern blot analysis of plasmids isolated from TetR colonies [5].

High impact information on tetR

• The first component contains LexA binding sites upstream of the TetR gene and the second contains TetR operator binding sites upstream of HIS3 [6].
• Several TetR mutants that are non-inducible by tetracycline also respond to the peptide [7].
• The protein TetR-NLS, but not control protein TetR, specifically enhances gene expression from lipofected tetO-containing DNA between 4- and 16-fold [8].
• The high affinity and specificity of TetR for the short DNA sequence tetO was used in these studies to bind the NLS to DNA as demonstrated by the reduced electrophoretic mobility of the TetR.tetO-DNA complexes [8].
• These results establish that in addition to a region in the hydrophobic core residues at the solvent-exposed periphery of the dimerization surface participate in protein-protein recognition in the TetR four-helix bundle [9].

Chemical compound and disease context of tetR

• Tet repressor (TetR) is involved in the most abundant mechanism of tetracycline (Tc) resistance of gram-negative bacteria [3].

Biological context of tetR

• Contrary to dimeric TetR, scTetR allows the construction of scTetR mutants, in which one subunit contains a defective inducer binding site while the other is functional [10].
• The obtained results show that the mRNAs transcribed from both series of reporter genes (cat and tetR) were active in vivo [1].
• The efficiency of expression was evaluated by the yield of CAT (for the cat gene) and cell viability in increasing concentrations of antibiotic (for both cat and tetR genes) [1].
• The gene for the Tn 10 Tet repressor (TetR) was subjected to deletion mutagenesis [11].
• Thus, cooperation between residues at positions 37, 39, 41 and 42 in the HTH of TetR is necessary to optimize recognition of base-pair 4 [12].

Anatomical context of tetR

• TetR specifically binds to tetracyclines, enhances their fluorescence and thereby allows selective detection of tetracyclines that have crossed the membranes [13].
• To model an essential gene under tetracycline regulation, the E. coli hygromycin resistance gene, hph, was placed under the control of seven copies of the TetR binding site (tetO7) in a plasmid vector and co-transfected into A. fumigatus protoplasts together with one of the two transactivator plasmids [14].
• When added directly to cultured cells, TetR fused to the full-length Antennapedia homeodomain (AntpHD) from Drosophila (TetRAntp), was able to selectively repress transcription in cells transiently transfected with a tetracycline-regulated reporter transcription unit [15].

Associations of tetR with chemical compounds

• TetR N82A is not inducible under any of the conditions employed and shows an about 4000-fold decreased atc binding constant [16].
• Of all tc compounds tested so far, atc has the highest affinity for TetR, with a K(A) of 9.8 x 10(11) M(-1) in the presence of Mg(2+) and 6.5 x 10(7) M(-1) without Mg(2+) [16].
• In addition, a number of predicted genes, including those encoding enzymes in glycolysis and the pentose cycle, serine proteases, transcriptional regulators (MerR, LysR, and TetR families), histidine kinases, and hypothetical proteins were induced [17].
• In this paper we investigate the fluorescence properties of W43 of TetR upon binding of tetracycline inducer and its chemical analogs such as anhydro- and epitetracycline [18].

Analytical, diagnostic and therapeutic context of tetR

• The Escherichia coli tet-repressor (TetR) operator system was used to develop a variation of the yeast two-hybrid assay in which disruptions of protein-protein interactions can be identified by a positive selection [6].
• Restriction enzymes for cloning are so chosen that the only legitimate two fragment ligation yielding TetR clones involves a fragment spanning the boundary of the insertion [19].
• A protocol containing anion-exchange, cation-exchange, and size-exclusion chromatography steps is described for the large-scale purification of milligram amounts of TetR in three days [20].
• Circular dichroism studies of the TetR-[Mg.tc]+ complex do not indicate dramatic changes in the secondary structure of the protein; however, the observed small decrease in the TetR helicity may occur due to partial unfolding of the DNA recognition helix of the protein [18].

References