2rf4

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spinqualitylabelsall models 2rf4, resolution 3.1Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of the RNA Polymerase I subcomplex A14/43

Overview

Synthesis of ribosomal RNA (rRNA) by RNA polymerase (Pol) I is the first, step in ribosome biogenesis and a regulatory switch in eukaryotic cell, growth. Here we report the 12 A cryo-electron microscopic structure for, the complete 14-subunit yeast Pol I, a homology model for the core enzyme, and the crystal structure of the subcomplex A14/43. In the resulting, hybrid structure of Pol I, A14/43, the clamp, and the dock domain, contribute to a unique surface interacting with promoter-specific, initiation factors. The Pol I-specific subunits A49 and A34.5 form a, heterodimer near the enzyme funnel that acts as a built-in elongation, factor and is related to the Pol II-associated factor TFIIF. In contrast, to Pol II, Pol I has a strong intrinsic 3'-RNA cleavage activity, which, requires the C-terminal domain of subunit A12.2 and, apparently, enables, ribosomal RNA proofreading and 3'-end trimming.

About this Structure

2RF4 is a Protein complex structure of sequences from Saccharomyces cerevisiae. Active as DNA-directed RNA polymerase, with EC number 2.7.7.6 Full crystallographic information is available from OCA.

Reference

Functional architecture of RNA polymerase I., Kuhn CD, Geiger SR, Baumli S, Gartmann M, Gerber J, Jennebach S, Mielke T, Tschochner H, Beckmann R, Cramer P, Cell. 2007 Dec 28;131(7):1260-72. PMID:18160037

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