Related ArticlesOligomerization of the EK18 mutant of the trp repressor of Escherichia coli as observed by NMR spectroscopy.
Arch Biochem Biophys. 1999 Nov 1;371(1):35-40
Authors: Chae YK, Abildgaard F, Royer CA, Markley JL
The regulation of the trp repressor system of Escherichia coli is frequently modeled by a single equilibrium, that between the aporepressor (TR) and the corepressor, l-tryptophan (Trp), at their intracellular concentrations. The actual mechanism, which is much more complex and more finely tuned, involves multiple equilibria: TR and Trp association, TR oligomerization, specific and nonspecific binding of various states of TR to DNA, and interactions between these various species and ions. TR in isolation exists primarily as a homodimer, but the state of oligomerization increases as the TR concentration goes up and/or the salt concentration goes down, leading to species with lower affinity for DNA. We have used multinuclear, multidimensional NMR spectroscopy to investigate structural changes that accompany the oligomerization of TR. For these investigations, the superrepressor mutant EK18 (TR with Glu 18 replaced by Lys) was chosen because it exhibits less severe oligomerization at higher protein concentration than other known variants; this made it possible to study the dimer to tetramer oligomerization step by NMR. The NMR results suggest that the interaction between TR dimers is structurally linked to folding of the DNA binding domain and that it likely involves direct contacts between the C-terminal residues of the C-helix of one dimer with the next dimer. This implies that oligomerization can compete with DNA binding and thus serves as a factor in the fine-tuning of gene expression.
[NMR paper] NMR characterization of a single-cysteine mutant of Escherichia coli thioredoxin and
NMR characterization of a single-cysteine mutant of Escherichia coli thioredoxin and a covalent thioredoxin-peptide complex.
Related Articles NMR characterization of a single-cysteine mutant of Escherichia coli thioredoxin and a covalent thioredoxin-peptide complex.
Eur J Biochem. 1998 Oct 15;257(2):299-308
Authors: Jeng MF, Reymond MT, Tennant LL, Holmgren A, Dyson HJ
The mechanism of disulfide reduction by thioredoxin in the cell is thought to occur through the formation and subsequent destruction of a mixed-disulfide intermediate between...
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[NMR paper] NMR studies of the Escherichia coli Trp repressor.trpRs operator complex.
NMR studies of the Escherichia coli Trp repressor.trpRs operator complex.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles NMR studies of the Escherichia coli Trp repressor.trpRs operator complex.
Eur J Biochem. 1996 Dec 15;242(3):567-75
Authors: Evans PD, Jaseja M, Jeeves M, Hyde EI
To understand the specificity of the Escherichia coli Trp repressor for its operators, we have begun to study complexes of the protein with...
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[NMR paper] Dynamics of tryptophan binding to Escherichia coli Trp repressor wild type and AV77 m
Dynamics of tryptophan binding to Escherichia coli Trp repressor wild type and AV77 mutant: an NMR study.
Related Articles Dynamics of tryptophan binding to Escherichia coli Trp repressor wild type and AV77 mutant: an NMR study.
Biochemistry. 1995 Oct 10;34(40):13183-9
Authors: Schmitt TH, Zheng Z, Jardetzky O
Binding of L-tryptophan to Escherichia coli trp repressor wild type (WT) and AV77 mutant was studied by 1H NMR spectroscopy. Ligand binding to the proteins resulted in changes in line widths and chemical shifts of ligand resonances, but...
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[NMR paper] Characterization by 1H NMR of a C32S,C35S double mutant of Escherichia coli thioredox
Characterization by 1H NMR of a C32S,C35S double mutant of Escherichia coli thioredoxin confirms its resemblance to the reduced wild-type protein.
Related Articles Characterization by 1H NMR of a C32S,C35S double mutant of Escherichia coli thioredoxin confirms its resemblance to the reduced wild-type protein.
FEBS Lett. 1994 Feb 14;339(1-2):11-7
Authors: Dyson HJ, Jeng MF, Model P, Holmgren A
A mutant of Escherichia coli thioredoxin containing serine residues in place of the two active-site cysteines, termed C32S,C35S, previously shown to be...
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[NMR paper] The interactions of Escherichia coli trp repressor with tryptophan and with an operat
The interactions of Escherichia coli trp repressor with tryptophan and with an operator oligonucleotide. NMR studies using selectively 15N-labelled protein.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles The interactions of Escherichia coli trp repressor with tryptophan and with an operator oligonucleotide. NMR studies using selectively 15N-labelled protein.
Eur J Biochem. 1994 Oct 15;225(2):601-8
Authors: Ramesh V, Frederick RO, Syed SE,...
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[NMR paper] Sequence-specific NMR assignments of the trp repressor from Escherichia coli using th
Sequence-specific NMR assignments of the trp repressor from Escherichia coli using three-dimensional 15N/1H heteronuclear techniques.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles Sequence-specific NMR assignments of the trp repressor from Escherichia coli using three-dimensional 15N/1H heteronuclear techniques.
Eur J Biochem. 1992 Feb 15;204(1):137-46
Authors: Borden KL, Bauer CJ, Frenkiel TA, Beckmann P, Lane AN
...
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[NMR paper] NMR studies of the activation of the Escherichia coli trp repressor.
NMR studies of the activation of the Escherichia coli trp repressor.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles NMR studies of the activation of the Escherichia coli trp repressor.
Eur J Biochem. 1991 Nov 1;201(3):569-79
Authors: Hyde EI, Ramesh V, Frederick R, Roberts GC
The Escherichia coli trp repressor binds to the trp operator in the presence of tryptophan, thereby inhibiting tryptophan biosynthesis. Tryptophan analogues...
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[NMR paper] NMR studies of the activation of the Escherichia coli trp repressor.
NMR studies of the activation of the Escherichia coli trp repressor.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles NMR studies of the activation of the Escherichia coli trp repressor.
Eur J Biochem. 1991 Nov 1;201(3):569-79
Authors: Hyde EI, Ramesh V, Frederick R, Roberts GC
The Escherichia coli trp repressor binds to the trp operator in the presence of tryptophan, thereby inhibiting tryptophan biosynthesis. Tryptophan analogues...