2o5i
From Proteopedia
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Crystal structure of the T. thermophilus RNA polymerase elongation complex
Overview
The RNA polymerase elongation complex (EC) is both highly stable and, processive, rapidly extending RNA chains for thousands of nucleotides., Understanding the mechanisms of elongation and its regulation requires, detailed information about the structural organization of the EC. Here we, report the 2.5-A resolution structure of the Thermus thermophilus EC; the, structure reveals the post-translocated intermediate with the DNA template, in the active site available for pairing with the substrate. DNA strand, separation occurs one position downstream of the active site, implying, that only one substrate at a time can specifically bind to the EC. The, upstream edge of the RNA/DNA hybrid stacks on the beta'-subunit 'lid', loop, whereas the first displaced RNA base is trapped within a protein, pocket, suggesting a mechanism for RNA displacement. The RNA is threaded, through the RNA exit channel, where it adopts a conformation mimicking, that of a single strand within a double helix, providing insight into a, mechanism for hairpin-dependent pausing and termination.
About this Structure
2O5I is a Protein complex structure of sequences from Thermus thermophilus with ZN and MG as ligands. Active as DNA-directed RNA polymerase, with EC number 2.7.7.6 Full crystallographic information is available from OCA.
Reference
Structural basis for transcription elongation by bacterial RNA polymerase., Vassylyev DG, Vassylyeva MN, Perederina A, Tahirov TH, Artsimovitch I, Nature. 2007 Jun 20;. PMID:17581590
Page seeded by OCA on Wed Nov 21 13:03:44 2007
