Disease relevance of pIGAL1_02

• Positive and negative regulation of the Mu operator by Mu repressor and Escherichia coli integration host factor [1].
• (iv) Only a small fraction of the lysogens in a culture spontaneously induce and when the lysogen carries two lambdoid prophages with different repressor/operators, 933W and H-19B, usually both prophages in the same cell are induced [2].
• Separate E. coli K-12 RV308 host strains containing the new recombinants were lysogenized with the repressor-defective bacteriophage lambda cI90 [3].
• We have examined the positions of contact between lambda phage repressor protein and operator OR1 DNA by scanning populations of lightly depurinated or depyrimidated DNA for bases essential to or irrelevant to repressor binding [4].
• The Bacillus subtilis phage phi 105 repressor, a lambda repressor-like transcriptional regulatory protein, was overproduced in Escherichia coli and purified to near homogeneity in order to examine its in vitro DNA-binding properties [5].

High impact information on pIGAL1_02

• Regulation of transcription initiation is generally attributable to activator/repressor proteins that bind to specific DNA sequences [6].
• Purified Mu repressor, in addition to its primary binding in the operator region, also binds less strongly to the Mu ends at the same sites as the Mu A protein [7].
• E. coli ribosomal protein L1 is a translational repressor of the synthesis in vitro of both proteins encoded in the L11 operon (L11 and L1) [8].
• Feedback regulation of ribosomal protein synthesis in E. coli: localization of the mRNA target sites for repressor action of ribosomal protein L1 [8].
• Although previous work indicated that translationally inhibited ribosomal protein mRNA is degraded in vivo, L1 repressor action in the present in vitro system was found not to involve mRNA degradation [8].

Chemical compound and disease context of pIGAL1_02

• The tryptophan gene (trp) repressor of Escherichia coli has been converted into a site-specific nuclease by covalently attaching it to the 1,10-phenanthroline-copper complex [9].
• We constructed plasmids that, in Escherichia coli, direct the expression of derivatives of lambda repressor that lack the NH2-terminal one, three, six, or seven amino acids [10].
• Overproduction and rapid purification of the biotin operon repressor from Escherichia coli [11].
• ArsD is a trans-acting repressor of the arsRDABC operon that confers resistance to arsenicals and antimonials in Escherichia coli [12].
• Constitutive expression of tetracycline resistance mediated by a Tn10-like element in Haemophilus parainfluenzae results from a mutation in the repressor gene [13].

Biological context of pIGAL1_02

• Messenger RNA encoding the repressor gene is synthesized leftward from a promoter (PcM) located 1066 base pairs from the Mu left end [1].
• Thus, maintenance of the lysogenic state and autoregulation of the repressor gene is achieved by RNA polymerase transcription through DNA-repressor ensembles at O1 and O2 [1].
• The transposase and repressor mRNAs are transcribed divergently and their transcription initiation sites are separated by 80 bp [14].
• In addition, the chromosomally-encoded repressor can regulate expression of the ars operon of plasmid R773, and the R773 repressor can cross-regulate expression from the chromosomal operon [15].
• The results of gel mobility shift assays indicated that the repressor is a DNA binding protein that binds to a fragment of DNA containing the chromosomal ars promoter [15].

Anatomical context of pIGAL1_02

• In order to study the DNA binding activity of the repressor, the structural gene for blaI, from strain 749, with its ribosome binding site was expressed using a two plasmid T7 RNA polymerase/promotor system (S [16].

Associations of pIGAL1_02 with chemical compounds

• On the transcriptional regulation of methicillin resistance: MecI repressor in complex with its operator [17].
• In this work, a structure determined by x-ray crystallography of a complex of the repressor bound to biotin, which also functions as an activator of DNA binding by the biotin repressor (BirA), is described [18].
• Cyclic AMP-dependent constitutive expression of gal operon: use of repressor titration to isolate operator mutations [19].
• The fluorescence of tetracycline is enhanced upon binding to Tet repressor [20].
• Mutants of the Tn10-encoded Tet repressor containing single or no tryptophan residues were constructed by oligonucleotide-directed mutagenesis [20].

Regulatory relationships of pIGAL1_02

• The results demonstrate that expression of the resistance gene tetA is regulated by Tet repressor bound to either O1 or O2 [21].

Other interactions of pIGAL1_02

• A two-plasmid system in which one plasmid served as substrate while the other encoded both resolvase and a thermolabile repressor of resolvase transcription provided controlled, synchronous recombination [22].
• Expression of the repressor gene tetR is only marginally reduced when Tet repressor is bound to O2 [21].
• Mutations in three of the four cysteine residues of merR resulted in complete loss of Hg(II)-inducible activation but retention of the repressor function, suggesting that these residues serve as ligands for Hg(II) in the activation process [23].
• We propose that two similar regions of dyad symmetry within the Tn10 tet regulatory region are operator sites at which tet repressor binds to tet DNA, thereby inhibiting transcription initiation at the tetA and tetR promoters [24].
• We have localized the D108 thermosensitive (cts) repressor gene to a region of DNA approx. 600 base pairs (bp) in length by sub-cloning an RsaI restriction endonuclease fragment (bp 200 to bp 802 from the left-end of the D108 genome) [25].

Analytical, diagnostic and therapeutic context of pIGAL1_02

• Three mutations have been constructed by oligonucleotide-directed mutagenesis which reduce binding of Tet repressor to either one or both of the tandem tet operators 1000-fold as determined by DNAseI footprinting in vitro [21].
• Crystallization of the bifunctional biotin operon repressor [26].
• We have shown that Gal repressor binding to OE or OI DNA fragments increases the circular dichroism (CD) spectral peak in the 270 to 300 nm range [27].

References