Molecular cell, 2019-07, Vol.75 (2), p.298-309.e4
2019
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- Autor(en) / Beteiligte
- Titel
- Structural Basis of Transcription: RNA Polymerase Backtracking and Its Reactivation
- Ist Teil von
- Molecular cell, 2019-07, Vol.75 (2), p.298-309.e4
- Ort / Verlag
- United States: Elsevier Inc
- Erscheinungsjahr
- 2019
- Quelle
- MEDLINE
- Beschreibungen/Notizen
- Regulatory sequences or erroneous incorporations during DNA transcription cause RNA polymerase backtracking and inactivation in all kingdoms of life. Reactivation requires RNA transcript cleavage. Essential transcription factors (GreA and GreB, or TFIIS) accelerate this reaction. We report four cryo-EM reconstructions of Escherichia coli RNA polymerase representing the entire reaction pathway: (1) a backtracked complex; a backtracked complex with GreB (2) before and (3) after RNA cleavage; and (4) a reactivated, substrate-bound complex with GreB before RNA extension. Compared with eukaryotes, the backtracked RNA adopts a different conformation. RNA polymerase conformational changes cause distinct GreB states: a fully engaged GreB before cleavage; a disengaged GreB after cleavage; and a dislodged, loosely bound GreB removed from the active site to allow RNA extension. These reconstructions provide insight into the catalytic mechanism and dynamics of RNA cleavage and extension and suggest how GreB targets backtracked complexes without interfering with canonical transcription. [Display omitted] •Cryo-EM structures of RNA polymerase cover backtracking, cleavage, and reactivation•Backtracking allows active site access for GreB, and backtracked RNA stabilizes GreB•GreB needs to leave the active site for substrate binding•Substrate binding induces global conformational change in RNA polymerase Abdelkareem et al. present four cryo-EM structures of active RNA polymerase representing backtracking and transcription factor-assisted cleavage and reactivation: (1) a backtracked complex; a backtracked complex with GreB (2) before and (3) after RNA cleavage; and (4) a reactivated, substrate-bound complex resuming transcription.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 1097-2765eISSN: 1097-4164DOI: 10.1016/j.molcel.2019.04.029Titel-ID: cdi_pubmedcentral_primary_oai_pubmedcentral_nih_gov_7611809
- Format
- –
- Schlagworte
- Amino Acid Sequence - genetics, backtracking, Catalytic Domain - genetics, cryo-EM, Cryoelectron Microscopy, DNA-Directed RNA Polymerases - chemistry, DNA-Directed RNA Polymerases - genetics, Escherichia coli - chemistry, Escherichia coli - genetics, Escherichia coli Proteins - chemistry, Escherichia coli Proteins - genetics, GreB, Life Sciences, Multiprotein Complexes - chemistry, Multiprotein Complexes - genetics, Protein Binding, Protein Conformation, RNA - chemistry, RNA - genetics, RNA Cleavage - genetics, RNA polymerase structure, RNA-Binding Motifs - genetics, transcription, Transcription Factors - chemistry, Transcription Factors - genetics, Transcription, Genetic, transcriptional arrest, Transcriptional Elongation Factors - chemistry, Transcriptional Elongation Factors - genetics, transcriptional rescue