National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)
DP5 OD021396
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM121975
米国
引用
ジャーナル: Nat Commun / 年: 2020 タイトル: Molecular determinants for dsDNA translocation by the transcription-repair coupling and evolvability factor Mfd. 著者: Christiane Brugger / Cheng Zhang / Margaret M Suhanovsky / David D Kim / Amy N Sinclair / Dmitry Lyumkis / Alexandra M Deaconescu / 要旨: Mfd couples transcription to nucleotide excision repair, and acts on RNA polymerases when elongation is impeded. Depending on impediment severity, this action results in either transcription ...Mfd couples transcription to nucleotide excision repair, and acts on RNA polymerases when elongation is impeded. Depending on impediment severity, this action results in either transcription termination or elongation rescue, which rely on ATP-dependent Mfd translocation on DNA. Due to its role in antibiotic resistance, Mfd is also emerging as a prime target for developing anti-evolution drugs. Here we report the structure of DNA-bound Mfd, which reveals large DNA-induced structural changes that are linked to the active site via ATPase motif VI. These changes relieve autoinhibitory contacts between the N- and C-termini and unmask UvrA recognition determinants. We also demonstrate that translocation relies on a threonine in motif Ic, widely conserved in translocases, and a family-specific histidine near motif IVa, reminiscent of the "arginine clamp" of RNA helicases. Thus, Mfd employs a mode of DNA recognition that at its core is common to ss/ds translocases that act on DNA or RNA.
凍結剤: ETHANE / チャンバー内温度: 277 K / 装置: HOMEMADE PLUNGER 詳細: 2.5ul Mfd-DNA complex at 1.0 mg/mL was applied to UltrAuFoil R1.2/1.3 300 mesh grids (Quantifoil) that were previously plasma-cleaned using a Gatan Solarus (75% argon/25% oxygen atmosphere, ...詳細: 2.5ul Mfd-DNA complex at 1.0 mg/mL was applied to UltrAuFoil R1.2/1.3 300 mesh grids (Quantifoil) that were previously plasma-cleaned using a Gatan Solarus (75% argon/25% oxygen atmosphere, 15 W for 7s), then manually blotted with a Whatman No. 1 filter paper in a cold room with >80% humidity, and plunged into liquid ethane using a manual plunger.