Structural highlights
Function
[GREB_ECOL6] Necessary for efficient RNA polymerase transcription elongation past template-encoded arresting sites. The arresting sites in DNA have the property of trapping a certain fraction of elongating RNA polymerases that pass through, resulting in locked ternary complexes. Cleavage of the nascent transcript by cleavage factors such as GreA or GreB allows the resumption of elongation from the new 3'terminus. GreB releases sequences of up to 9 nucleotides in length (By similarity).
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Bacterial Gre transcript cleavage factors stimulate the intrinsic endonucleolytic activity of RNA polymerase (RNAP) to rescue stalled transcription complexes. They bind to RNAP and extend their coiled-coil (CC) domains to the catalytic centre through the secondary channel. Three existing models for the Gre-RNAP complex postulate congruent mechanisms of Gre-assisted catalysis, while offering conflicting views of the Gre-RNAP interactions. Here, we report the GreB structure of Escherichia coli. The GreB monomers form a triangle with the tip of the amino-terminal CC of one molecule trapped within the hydrophobic cavity of the carboxy-terminal domain of a second molecule. This arrangement suggests an analogous model for recruitment to RNAP. Indeed, the beta'-subunit CC located at the rim of the secondary channel has conserved hydrophobic residues at its tip. We show that substitutions of these residues and those in the GreB C-terminal domain cavity confer defects in GreB activity and binding to RNAP, and present a plausible model for the RNAP-GreB complex.
The carboxy-terminal coiled-coil of the RNA polymerase beta'-subunit is the main binding site for Gre factors.,Vassylyeva MN, Svetlov V, Dearborn AD, Klyuyev S, Artsimovitch I, Vassylyev DG EMBO Rep. 2007 Nov;8(11):1038-43. Epub 2007 Oct 5. PMID:17917675[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Vassylyeva MN, Svetlov V, Dearborn AD, Klyuyev S, Artsimovitch I, Vassylyev DG. The carboxy-terminal coiled-coil of the RNA polymerase beta'-subunit is the main binding site for Gre factors. EMBO Rep. 2007 Nov;8(11):1038-43. Epub 2007 Oct 5. PMID:17917675
