6rip

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

6rip, resolution 3.40Å Show:Asymmetric Unit Biological Assembly Structural highlights 6rip is a 8 chain structure with sequence from Escherichia coli and Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.4Å Ligands: Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RPOA_ECOLI DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. This subunit plays an important role in subunit assembly since its dimerization is the first step in the sequential assembly of subunits to form the holoenzyme.[HAMAP-Rule:MF_00059] Publication Abstract from PubMed 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. Structural Basis of Transcription: RNA Polymerase Backtracking and Its Reactivation.,Abdelkareem M, Saint-Andre C, Takacs M, Papai G, Crucifix C, Guo X, Ortiz J, Weixlbaumer A Mol Cell. 2019 May 8. pii: S1097-2765(19)30321-1. doi:, 10.1016/j.molcel.2019.04.029. PMID:31103420 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also RNA polymerase 3D structures