2W53

Structure of SmeT, the repressor of the Stenotrophomonas maltophilia multidrug efflux pump SmeDEF.

2W53 の概要

• エントリーDOI: 10.2210/pdb2w53/pdb
• 分子名称: REPRESSOR, SULFATE ION (3 entities in total)
• 機能のキーワード: antibiotic resistance, multi-drug efflux pump, transcription regulation, transcriptional repressor, dna binding, tetr family, dna-binding, transcription
• 由来する生物種: STENOTROPHOMONAS MALTOPHILIA
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 49484.86

構造登録者

Mate, M.J.,Romero, A.,Hernandez, A.,Martinez, J.L. (登録日: 2008-12-04, 公開日: 2009-04-07, 最終更新日: 2024-05-08)

主引用文献

Hernandez, A.,Mate, M.J.,Sanchez, P.,Romero, A.,Rojo, F.,Martinez, J.L.
Structural and Functional Analysis of Smet, the Repressor of the Stenotrophomonas Maltophilia Multidrug Efflux Pump Smedef.
J.Biol.Chem., 284:14428-, 2009

PubMed Abstract: Stenotrophomonas maltophilia is an opportunistic pathogen characterized for its intrinsic low susceptibility to several antibiotics. Part of this low susceptibility relies on the expression of chromosomally encoded multidrug efflux pumps, with SmeDEF being the most relevant antibiotic resistance efflux pump so far studied in this bacterial species. Expression of smeDEF is down-regulated by the SmeT repressor, encoded upstream smeDEF, in its complementary DNA strand. In the present article we present the crystal structure of SmeT and analyze its interactions with its cognate operator. Like other members of the TetR family of transcriptional repressors, SmeT behaves as a dimer and presents some common structural features with other TetR proteins like TtgR, QacR, and TetR. Differing from other TetR proteins for which the structure is available, SmeT turned out to have two extensions at the N and C termini that might be relevant for its function. Besides, SmeT presents the smallest binding pocket so far described in the TetR family of transcriptional repressors, which may correlate with a specific type and range of effectors. In vitro studies revealed that SmeT binds to a 28-bp pseudopalindromic region, forming two complexes. This operator region was found to overlap the promoters of smeT and smeDEF. This finding is consistent with a role for SmeT simultaneously down-regulating smeT and smeDEF transcription, likely by steric hindrance on RNA polymerase binding to DNA.

PubMed: 19324881
DOI: 10.1074/JBC.M809221200

実験手法

X-RAY DIFFRACTION (2 Å)