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-Structure paper
Title | Pol IV and RDR2: A two-RNA-polymerase machine that produces double-stranded RNA. |
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Journal, issue, pages | Science, Vol. 374, Issue 6575, Page 1579-1586, Year 2021 |
Publish date | Dec 24, 2021 |
Authors | Kun Huang / Xiao-Xian Wu / Cheng-Li Fang / Zhou-Geng Xu / Hong-Wei Zhang / Jian Gao / Chuan-Miao Zhou / Lin-Lin You / Zhan-Xi Gu / Wen-Hui Mu / Yu Feng / Jia-Wei Wang / Yu Zhang / |
PubMed Abstract | DNA methylation affects gene expression and maintains genome integrity. The DNA-dependent RNA polymerase IV (Pol IV), together with the RNA-dependent RNA polymerase RDR2, produces double-stranded ...DNA methylation affects gene expression and maintains genome integrity. The DNA-dependent RNA polymerase IV (Pol IV), together with the RNA-dependent RNA polymerase RDR2, produces double-stranded small interfering RNA precursors essential for establishing and maintaining DNA methylation in plants. We determined the cryo–electron microscopy structures of the Pol IV–RDR2 holoenzyme and the backtracked transcription elongation complex. These structures reveal that Pol IV and RDR2 form a complex with their active sites connected by an interpolymerase channel, through which the Pol IV–generated transcript is handed over to the RDR2 active site after being backtracked, where it is used as the template for double-stranded RNA (dsRNA) synthesis. Our results describe a ‘backtracking-triggered RNA channeling’ mechanism underlying dsRNA synthesis and also shed light on the evolutionary trajectory of eukaryotic RNA polymerases. |
External links | Science / PubMed:34941388 |
Methods | EM (single particle) |
Resolution | 3.16 - 3.86 Å |
Structure data | EMDB-31305, PDB-7eu0: EMDB-31306, PDB-7eu1: |
Chemicals | ChemComp-ZN: ChemComp-MG: |
Source |
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Keywords | TRANSCRIPTION / DNA-directed RNA polymerase IV / RNA- dependent RNA polymerase 2 / RNA-directed DNA methylation pathway / TRANSPORT PROTEIN |