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Publication Abstract from PubMed

In addition to the conserved RNA polymerases I to III (Pols I to III) in eukaryotes, two atypical polymerases, Pols IV and V, specifically produce noncoding RNA in the RNA-directed DNA methylation 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 double-stranded DNA branch of the transcription bubble to potentially attenuate elongation by inducing transcription stalling. The nontemplate 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 RNA-directed DNA methylation.

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 24;379(6638):1209-1213. doi: 10.1126/science.adf8231. Epub 2023 , Mar 9. PMID:36893216^[1]

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