ジャーナル: Mol Cell / 年: 2018 タイトル: Structural Basis of Transcription Inhibition by Fidaxomicin (Lipiarmycin A3). 著者: Wei Lin / Kalyan Das / David Degen / Abhishek Mazumder / Diego Duchi / Dongye Wang / Yon W Ebright / Richard Y Ebright / Elena Sineva / Matthew Gigliotti / Aashish Srivastava / Sukhendu ...著者: Wei Lin / Kalyan Das / David Degen / Abhishek Mazumder / Diego Duchi / Dongye Wang / Yon W Ebright / Richard Y Ebright / Elena Sineva / Matthew Gigliotti / Aashish Srivastava / Sukhendu Mandal / Yi Jiang / Yu Liu / Ruiheng Yin / Zhening Zhang / Edward T Eng / Dennis Thomas / Stefano Donadio / Haibo Zhang / Changsheng Zhang / Achillefs N Kapanidis / Richard H Ebright / 要旨: Fidaxomicin is an antibacterial drug in clinical use for treatment of Clostridium difficile diarrhea. The active ingredient of fidaxomicin, lipiarmycin A3 (Lpm), functions by inhibiting bacterial ...Fidaxomicin is an antibacterial drug in clinical use for treatment of Clostridium difficile diarrhea. The active ingredient of fidaxomicin, lipiarmycin A3 (Lpm), functions by inhibiting bacterial RNA polymerase (RNAP). Here we report a cryo-EM structure of Mycobacterium tuberculosis RNAP holoenzyme in complex with Lpm at 3.5-Å resolution. The structure shows that Lpm binds at the base of the RNAP "clamp." The structure exhibits an open conformation of the RNAP clamp, suggesting that Lpm traps an open-clamp state. Single-molecule fluorescence resonance energy transfer experiments confirm that Lpm traps an open-clamp state and define effects of Lpm on clamp dynamics. We suggest that Lpm inhibits transcription by trapping an open-clamp state, preventing simultaneous interaction with promoter -10 and -35 elements. The results account for the absence of cross-resistance between Lpm and other RNAP inhibitors, account for structure-activity relationships of Lpm derivatives, and enable structure-based design of improved Lpm derivatives.
pH: 8 詳細: 3.5 microliter 1 microM Mtb RNAP-Lpm and 50 microMolar Lpm in 20 mM Tris-HCl, pH 8.0, 75 mM NaCl, 5 mM MgCl2, 5 mM dithiothreitol, and 0.1% n-octyl-beta-D-glucopyranoside
フィルム・検出器のモデル: GATAN K2 SUMMIT (4k x 4k) 検出モード: COUNTING / デジタル化 - サイズ - 横: 3838 pixel / デジタル化 - サイズ - 縦: 3710 pixel / デジタル化 - 画像ごとのフレーム数: 1-35 / 撮影したグリッド数: 2 / 実像数: 2458 / 平均露光時間: 0.2 sec. / 平均電子線量: 1.4 e/Å2 詳細: Movies were recorded at 200 ms/frame for 10s (50 frames total), resulting in a total radiation dose of 72.05 electrons/A**2 per movie Defocus range was varied between 1.0 - 2.0 micrometer.