HTH-type transcriptional regulator EthR is involved in the repression of the monooxygenase EthA which is responsible of the formation of the active metabolite of ethionamide (ETH). It is responsible for the low sensitivity of the human pathogen Mycobacterium tuberculosis to ethionamide. It consists of a DNA-binding HTH domain at the N-terminal and a C-terminal helical domain that binds its ligand [1-5].

1: Crystal structure of the TetR/CamR family repressor Mycobacterium tuberculosis EthR implicated in ethionamide resistance. Dover LG, Corsino PE, Daniels IR, Cocklin SL, Tatituri V, Besra GS, Futterer K; J Mol Biol. 2004;340:1095-1105. PMID:15236969

2: Structure of EthR in a ligand bound conformation reveals therapeutic perspectives against tuberculosis. Frenois F, Engohang-Ndong J, Locht C, Baulard AR, Villeret V; Mol Cell. 2004;16:301-307. PMID:15494316

3: Synthetic EthR inhibitors boost antituberculous activity of ethionamide. Willand N, Dirie B, Carette X, Bifani P, Singhal A, Desroses M, Leroux F, Willery E, Mathys V, Deprez-Poulain R, Delcroix G, Frenois F, Aumercier M, Locht C, Villeret V, Deprez B, Baulard AR; Nat Med. 2009;15:537-544. PMID:19412174

4: Structural activation of the transcriptional repressor EthR from Mycobacterium tuberculosis by single amino acid change mimicking natural and synthetic ligands. Carette X, Blondiaux N, Willery E, Hoos S, Lecat-Guillet N, Lens Z, Wohlkonig A, Wintjens R, Soror SH, Frenois F, Dirie B, Villeret V, England P, Lippens G, Deprez B, Locht C, Willand N, Baulard AR; Nucleic Acids Res. 2012;40:3018-3030. PMID:22156370

5: Ethionamide boosters. 2. Combining bioisosteric replacement and structure-based drug design to solve pharmacokinetic issues in a series of potent 1,2,4-oxadiazole EthR inhibitors. Flipo M, Desroses M, Lecat-Guillet N, Villemagne B, Blondiaux N, Leroux F, Piveteau C, Mathys V, Flament MP, Siepmann J, Villeret V, Wohlkonig A, Wintjens R, Soror SH, Christophe T, Jeon HK, Locht C, Brodin P, Deprez B, Baulard AR, Willand N; J Med Chem. 2012;55:68-83. PMID:22098589