title: Variations of subunit {varepsilon} of the Mycobacterium tuberculosis F1Fo ATP synthase and a novel model for mechanism of action of the tuberculosis drug TMC207.
abstract: The subunit ε of bacterial F(1)F(O) 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 ε of Mycobacterium tuberculosis (Mtε) F(1)F(O) ATP synthase and the nuclear magnetic resonance (NMR) structure of its C-terminal segment (Mtε(103-120)). Mtε is significantly shorter (61.6 Å) than forms of the subunit in other bacteria, reflecting a shorter C-terminal sequence, proposed to be important in coupling processes via the catalytic β subunit. The C-terminal segment displays an α-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 Mtε. A model for the interaction of TMC207 with both ε 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 ε and the c-ring, respectively. T19 and R37 of ε 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 F(1)F(O) ATP synthase in M. tuberculosis.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore.
authors.forename: Goran
authors.initials: G
authors.lastname: Biukovic
authors.forename: Sandip
authors.initials: S
authors.lastname: Basak
authors.forename: Malathy Sony Subramanian
authors.initials: MS
authors.lastname: Manimekalai
authors.forename: Sankaranarayanan
authors.initials: S
authors.lastname: Rishikesan
authors.forename: Manfred
authors.initials: M
authors.lastname: Roessle
authors.forename: Thomas
authors.initials: T
authors.lastname: Dick
authors.forename: Srinivasa P S
authors.initials: SP
authors.lastname: Rao
authors.forename: Cornelia
authors.initials: C
authors.lastname: Hunke
authors.forename: Gerhard
authors.initials: G
authors.lastname: Grüber
mesh_terms: D000595:Amino Acid Sequence; D000995:Antitubercular Agents / Q000737:chemistry*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics; D064687:Diarylquinolines; D004926:Escherichia coli / Q000235:genetics; D025261:Mitochondrial Proton-Translocating ATPases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics; D062105:Molecular Docking Simulation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009169:Mycobacterium tuberculosis / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology; D019906:Nuclear Magnetic Resonance, Biomolecular; D021122:Protein Subunits / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics; D011522:Protons; D011804:Quinolines / Q000737:chemistry*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D013050:Spectrometry, Fluorescence
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D064687:Diarylquinolines; D021122:Protein Subunits; D011522:Protons; D011804:Quinolines; D011994:Recombinant Proteins; C493870:bedaquiline; C474451:F1F0-ATP synthase; D025261:Mitochondrial Proton-Translocating ATPases