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Publication Abstract from PubMed

In addition to the conserved RNA polymerases (Pols) I-III in eukaryotes, two atypical polymerases, Pols IV and V, specifically produce non-coding RNA in the RNA-directed DNA methylation (RdDM) pathway in plants. Here, we report on the structures of cauliflower Pol V in the free and elongation conformations. A conserved tyrosine residue of NRPE2 stacks with a dsDNA branch of the transcription bubble to potentially attenuate elongation by inducing transcription stalling. The non-template DNA strand is captured by NRPE2 to enhance backtracking, thereby increasing 3'-5' cleavage which likely underpins Pol V's high fidelity. The structures also illuminate the mechanism of Pol V transcription stalling and enhanced backtracking which may be important for Pol V's retention on chromatin to serve its function in tethering downstream factors for RdDM.

Structure and mechanism of the plant RNA polymerase V.,Xie G, Du X, Hu H, Li S, Cao X, Jacobsen SE, Du J Science. 2023 Mar 9:eadf8231. doi: 10.1126/science.adf8231. PMID:36893216^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.