title: Insights into mechanisms of induction and ligands recognition in the transcriptional repressor EthR from Mycobacterium tuberculosis.
abstract: Mycobacterium tuberculosis EthR is a repressor of ethA, a gene encoding a mono-oxygenase required for the activation of the prodrug ethionamide. Two EthR crystal structures have been reported recently, either in a ligand-bound (Frenois F, Engohang-Ndong J, Locht C, Baulard AR, Villeret V. Mol Cell 2004; 16: 301-7) or in a presumed apo conformation (Dover LG, Corsino PE, Daniels IR, Cocklin SL, Tatituri V, Besra GS, Futterer K. J Mol Biol 2004; 340: 1095-105). In order to infer the EthR induction mechanism, we have compared these structures. It appears that the two structures are in a conformation incompatible with repressor function, due to the presence in both proteins of fortuitous and structurally unrelated ligands. This observation paves the way to the design of specific drugs that could increase the sensitivity of M. tuberculosis to ethionamide.
authors.affiliation: CNRS-UMR8525, Institut de Biologie de Lille-Institut Pasteur de Lille, 1 rue du Professeur Calmette, BP245 59019 Lille cedex, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Frénois
authors.forename: Alain R
authors.initials: AR
authors.lastname: Baulard
authors.forename: Vincent
authors.initials: V
authors.lastname: Villeret
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology; D015195:Drug Design; D005000:Ethionamide / Q000494:pharmacology; D006801:Humans; D008024:Ligands; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry*
chemical_list: D000995:Antitubercular Agents; C481661:EthR protein, Mycobacterium tuberculosis; D008024:Ligands; D012097:Repressor Proteins; D005000:Ethionamide