2VKE

Tet repressor class D complexed with cobalt and tetracycline

2VKE の概要

• エントリーDOI: 10.2210/pdb2vke/pdb
• 関連するPDBエントリー: 1A6I 1BJY 1BJZ 1DU7 1ORK 1QPI 2TCT 2TRT 2VKV
• 分子名称: TETRACYCLINE REPRESSOR PROTEIN CLASS D, TETRACYCLINE, COBALT (II) ION, ... (5 entities in total)
• 機能のキーワード: transcription, metal-binding, helix-turn-helix, transcription regulator, transcription regulation, metal coordination, antibiotic resistance, cobalt, repressor, magnesium, dna-binding
• 由来する生物種: ESCHERICHIA COLI
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 23898.06

構造登録者

Palm, G.J.,Hinrichs, W. (登録日: 2007-12-18, 公開日: 2008-07-01, 最終更新日: 2023-12-13)

主引用文献

Palm, G.J.,Lederer, T.,Orth, P.,Saenger, W.,Takahashi, M.,Hillen, W.,Hinrichs, W.
Specific Binding of Divalent Metal Ions to Tetracycline and to the Tet Repressor/Tetracycline Complex.
J.Biol.Inorg.Chem., 13:1097-, 2008

PubMed Abstract: Tetracyclines coordinate metal(II) ions under physiological conditions forming chelate complexes with their ketoenolate moiety at rings B and C. These metal(II) complexes are the biologically relevant molecules conferring the antibiotic character of the drug by inhibiting ribosomal protein biosynthesis in prokaryotes. The Tet repressor, TetR, is the molecular switch for tetracycline resistance determinants in gram-negative bacteria. TetR controls transcription of a gene encoding the integral membrane protein TetA, which mediates active efflux of a tetracycline-metal(II) cation, [MeTc](+), by equimolar antiport with a proton. We evaluated distinct characteristics of the metal binding by crystal structure determination of TetR/[MeTc](+) complexes and of association equilibrium constants of [MeTc](+) and TetR/[MeTc](+) complexes. Various divalent metal ions bind to the same octahedral coordination site, defined by a histidine side chain of TetR, the tetracycline, and three water molecules. Whereas association constants for [MeTc](+) vary within 3 orders of magnitude, association of the [MeTc](+) cation to TetR is very similar for all measured divalent metals. Taking intracellular cation concentrations into account, it is evident that no other metal ion can compete with Mg(2+) for TetR/[MeTc](+) complex formation.

PubMed: 18548290
DOI: 10.1007/S00775-008-0395-2

実験手法

X-RAY DIFFRACTION (1.62 Å)