@article {2303,
	title = {The crystal structure of MexR from Pseudomonas aeruginosa in complex with its antirepressor ArmR},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {105},
	number = {39},
	year = {2008},
	note = {ISI Document Delivery No.: 386WWTimes Cited: 15Cited Reference Count: 41Wilke, Mark S. Heller, Markus Creagh, A. Louise Haynes, Charles A. McIntosh, Lawrence P. Poole, Keith Strynadka, Natalie C. J.},
	month = {Sep},
	pages = {14832-14837},
	type = {Article},
	abstract = {The intrinsic antimicrobial resistance of the opportunistic human pathogen Pseudomonas aeruginosa is compounded in mutant strains that overexpress multidrug efflux pumps such as the prominent drug-proton antiporter, MexAB-OprM. The primary regulator of the mexAB-oprM operon is the MarR family repressor, MexR. An additional repressor, NalC, also regulates mexAB-oprM by controlling expression of ArmR, an antirepressor peptide that is hypothesized to prevent the binding of MexR to its cognate DNA operator via an allosteric protein-peptide interaction. To better understand how ArmR modulates MexR, we determined the MexR-binding region of ArmR as its C-terminal 25 residues and solved the crystal structure of MexR in a 2: 1 complex with this ArmR fragment at 1.8 angstrom resolution. This structure reveals that the C-terminal residues of ArmR form a kinked alpha-helix, which occupies a pseudo-symmetrical and largely hydrophobic binding cavity located at the centre of the MexR dimer. Although the ArmR-binding cavity partially overlaps with the small molecule effector-binding sites of other MarR family members, it possesses a larger and more complex binding surface to accommodate the greater size and specific physicochemical properties of a peptide effector. Comparison with the structure of apo-MexR reveals that ArmR stabilizes a dramatic conformational change that is incompatible with DNA-binding. Thus, this work defines the structural mechanism by which ArmR allosterically derepresses MexR-controlled gene expression in P. aeruginosa and reveals important insights into the regulation of multidrug resistance.},
	keywords = {DEINOCOCCUS-RADIODURANS, DNA-BINDING, EXPRESSION, GENE, gene regulation, MarR, MARR FAMILY, MECHANISM, mexAB-oprM, MULTIDRUG EFFLUX OPERON, OPRM, PA3719, protein peptide, REPRESSOR, TRANSCRIPTIONAL REGULATOR HUCR},
	isbn = {0027-8424},
	url = {<Go to ISI>://000261914300004},
	author = {Wilke, M. S. and Heller, M. and Creagh, A. L. and Haynes, C. A. and McIntosh, L. P. and Poole, K. and Strynadka, N. C. J.}
}
@article {3478,
	title = {MODULATION OF TRANSCRIPTION FACTOR ETS-1 DNA-BINDING - DNA-INDUCED UNFOLDING OF AN ALPHA-HELIX},
	journal = {Science},
	volume = {269},
	number = {5232},
	year = {1995},
	note = {ISI Document Delivery No.: RX194Times Cited: 143Cited Reference Count: 49},
	month = {Sep},
	pages = {1866-1869},
	type = {Article},
	abstract = {Conformational changes, including local protein folding, play important roles in protein-DNA interactions. Here, studies of the transcription factor Ets-1 provided evidence that local protein unfolding also can accompany DNA binding. Circular dichroism and partial proteolysis showed that the secondary structure of the Ets-1 DNA-binding domain is unchanged in the presence of DNA. In contrast, DNA allosterically induced the unfolding of an cr helix that lies within a flanking region involved in the negative regulation of DNA binding. These findings suggest a structural basis for the intramolecular inhibition of DNA binding and a mechanism for the cooperative partnerships that are common features of many eukaryotic transcription factors.},
	keywords = {BASIC REGION, CRYSTAL-STRUCTURE, DOMAIN, FAMILY, GCN4, INDUCED CONFORMATIONAL CHANGE, PROTEIN-KINASES, REPRESSOR, SEQUENCE, SUBUNITS},
	isbn = {0036-8075},
	url = {<Go to ISI>://A1995RX19400036},
	author = {Petersen, J. M. and Skalicky, J. J. and Donaldson, L. W. and McIntosh, L. P. and Alber, T. and Graves, B. J.}
}
