6RIP

Cryo-EM structure of E. coli RNA polymerase backtracked elongation complex in swiveled state

Summary for 6RIP

• Entry DOI: 10.2210/pdb6rip/pdb
• Related: 6RH3 6RI7 6RI9 6RIN
• EMDB information: 4893
• Descriptor: Non-template DNA, Template DNA, DNA-directed RNA polymerase subunit alpha, ... (9 entities in total)
• Functional Keywords: e. coli rna polymerase, backtracking, elongation complex, transcription
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 8
• Total formula weight: 418179.75

Authors

Abdelkareem, M.,Saint-Andre, C.,Takacs, M.,Papai, G.,Crucifix, C.,Guo, X.,Ortiz, J.,Weixlbaumer, A. (deposition date: 2019-04-24, release date: 2019-07-03, Last modification date: 2024-05-22)

Primary citation

Abdelkareem, M.,Saint-Andre, C.,Takacs, M.,Papai, G.,Crucifix, C.,Guo, X.,Ortiz, J.,Weixlbaumer, A.
Structural Basis of Transcription: RNA Polymerase Backtracking and Its Reactivation.
Mol.Cell, 75:298-309.e4, 2019

PubMed Abstract: 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.

PubMed: 31103420
DOI: 10.1016/j.molcel.2019.04.029

Experimental method

ELECTRON MICROSCOPY (3.4 Å)