Variations of Subunit ε of the Mycobacterium tuberculosis F1Fo ATP Synthase and a Novel Model for Mechanism of Action of the Tuberculosis Drug TMC207
Variations of Subunit ε of the Mycobacterium tuberculosis F1Fo ATP Synthase and a Novel Model for Mechanism of Action of the Tuberculosis Drug TMC207
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DOI：
10.1128/aac.01039-12
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发表时间：
2013-01-01
影响因子：
4.9
通讯作者：
Grueber, Gerhard
中科院分区：
文献类型：
--
作者：
Biukovic, Goran;Basak, Sandip;Grueber, Gerhard
细菌F1FO-ATP合成酶的亚基epsilon通过其C-末端结构域的构象转变在偶联和催化中起着重要的调节作用。在这里，我们提出了第一个结核分枝杆菌epsilon(Mt Epsilon)F1FO ATP合成酶的低分辨溶液结构及其C-末端片段(mt epsilon(103-120))的核磁共振结构。MT epsilon比其他细菌中的亚基形式明显更短(61.6埃)，反映了更短的C末端序列，这在通过催化β亚基进行耦合的过程中是重要的。由于精氨酸残基的存在，C-末端片段显示出α-螺旋结构和高度正的表面电荷。利用核磁共振光谱、荧光光谱和诱变作用，我们证明了新的结核病候选药物TMC207与质子转运C环结合，也与mt epsilon结合。提出了TMC207与epsilon和c-环的相互作用模型，认为TMC207通过分别与epsilon和c-环的残基W15和F50相互作用，在两个旋转的亚基之间形成楔形。Epsilon的T19和R37提供与药物分子必要的极性相互作用。这一新的TMC207作用机制模型为设计针对结核分枝杆菌F1FO-ATP合酶的新药奠定了基础。
The subunit epsilon of bacterial F1FO ATP synthases plays an important regulatory role in coupling and catalysis via conformational transitions of its C-terminal domain. Here we present the first low-resolution solution structure of epsilon of Mycobacterium tuberculosis (Mt epsilon) F1FO ATP synthase and the nuclear magnetic resonance (NMR) structure of its C-terminal segment (Mt epsilon(103-120)). Mt epsilon is significantly shorter (61.6 angstrom) than forms of the subunit in other bacteria, reflecting a shorter C-terminal sequence, proposed to be important in coupling processes via the catalytic beta subunit. The C-terminal segment displays an alpha-helical structure and a highly positive surface charge due to the presence of arginine residues. Using NMR spectroscopy, fluorescence spectroscopy, and mutagenesis, we demonstrate that the new tuberculosis (TB) drug candidate TMC207, proposed to bind to the proton translocating c-ring, also binds to Mt epsilon. A model for the interaction of TMC207 with both epsilon and the c-ring is presented, suggesting that TMC207 forms a wedge between the two rotating subunits by interacting with the residues W15 and F50 of epsilon and the c-ring, respectively. T19 and R37 of epsilon provide the necessary polar interactions with the drug molecule. This new model of the mechanism of TMC207 provides the basis for the design of new drugs targeting the F1FO ATP synthase in M. tuberculosis.