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A novel DNA-binding motif in MarA: the first structure for an AraC family transcriptional activator.
A crystal structure for a member of the AraC prokaryotic transcriptional activator family, MarA, in complex with its cognate DNA-binding site is described, finding extensive interactions between the recognition helices and the DNA major groove provide the sequence specificity. Expand
A method for determining the sedimentation behavior of enzymes: application to protein mixtures.
  • R. Martin, B. Ames
  • Medicine, Chemistry
  • The Journal of biological chemistry
  • 1 May 1961
Sucrose gradient centrifugation is found to be a suitable method for determining sedimentation coefficients of enzymes in protein mixtures and the sedimentation behavior of several of the enzymes in the pathway of histidine biosynthesis in S. typhimurium has been determined. Expand
Binding of purified multiple antibiotic-resistance repressor protein (MarR) to mar operator sequences.
  • R. Martin, J. Rosner
  • Biology, Medicine
  • Proceedings of the National Academy of Sciences…
  • 6 June 1995
Elevated expression of the marORAB multiple antibiotic-resistance operon enhances the resistance of Escherichia coli to various medically significant antibiotics. Transcription of the operon isExpand
Structural requirements for marbox function in transcriptional activation of mar/sox/rob regulon promoters in Escherichia coli: sequence, orientation and spatial relationship to the core promoter
It is found that only one marbox orientation is functional at a given location, and the functional orientation is determined by marbox location: marboxes that are 15 or more basepairs upstream of the −35 hexamer are oriented opposite those closer to the − 35 hexamer. Expand
The AraC transcriptional activators.
The AraC family of bacterial transcriptional activators regulate diverse genetic systems and growing evidence suggests that for the sugar metabolism activators, multiple binding sites upstream of the promoter anchor the activator in a repressing or nonactivating configuration. Expand
Purification and regulatory properties of MarA protein, a transcriptional activator of Escherichia coli multiple antibiotic and superoxide resistance promoters
The mar and soxRS systems use activators with very similar specificities and mechanisms of action to respond to different environmental signals to produce multiple antibiotic and superoxide resistance. Expand
Autoactivation of the marRAB multiple antibiotic resistance operon by the MarA transcriptional activator in Escherichia coli
Assays of marR::lacZ transcriptional fusions in marRAB deletion or soxRS deletion strains showed that the superoxide generator paraquat stimulate mar transcription via sox RS and that salicylate stimulates mar transcription both by antagonizing MarR and by a MarR-independent mechanism. Expand
Promoter discrimination by the related transcriptional activators MarA and SoxS: differential regulation by differential binding
MarA and SoxS are closely related proteins (≈45% identical) that transcriptionally activate a common set of unlinked genes, resulting in multiple antibiotic and superoxide resistance in EscherichiaExpand
Fis, an accessorial factor for transcriptional activation of the mar (multiple antibiotic resistance) promoter of Escherichia coli in the presence of the activator MarA, SoxS, or Rob
Fis acts as an accessory transcriptional activator at the mar promoter, a small DNA-binding and -bending protein, with a Kd of approximately 5 nM that binds to the "marbox" centered at -61.5 relative to the transcriptional start site. Expand
Probing the Escherichia coli transcriptional activator MarA using alanine-scanning mutagenesis: residues important for DNA binding and activation.
Alanine-scanning mutagenesis and DNA retardation analysis suggests that MarA activates transcription by at least two distinct mechanisms, and the important role of phosphate contacts in marbox affinity suggests that indirect readout contributes to binding site recognition by MarA. Expand