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-Structure paper
Title | Structure of plant RNA-DEPENDENT RNA POLYMERASE 2, an enzyme involved in small interfering RNA production. |
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Journal, issue, pages | Plant Cell, Vol. 34, Issue 6, Page 2140-2149, Year 2022 |
Publish date | May 24, 2022 |
Authors | Xuan Du / Zhenlin Yang / Alfredo Jose Florez Ariza / Qian Wang / Guohui Xie / Sisi Li / Jiamu Du / |
PubMed Abstract | In plants, the biogenesis of small interfering RNA (siRNA) requires a family of RNA-dependent RNA polymerases that convert single-stranded RNA (ssRNA) into double-stranded RNA (dsRNA), which is ...In plants, the biogenesis of small interfering RNA (siRNA) requires a family of RNA-dependent RNA polymerases that convert single-stranded RNA (ssRNA) into double-stranded RNA (dsRNA), which is subsequently cleaved into defined lengths by Dicer endonucleases. Here, we determined the structure of maize (Zea mays) RNA-DEPENDENT RNA POLYMERASE 2 (ZmRDR2) in the closed and open conformations. The core catalytic region of ZmRDR2 possesses the canonical DNA-dependent RNA polymerase (DdRP) catalytic sites, pointing to a shared RNA production mechanism between DdRPs and plant RDR-family proteins. Apo-ZmRDR2 adopts a highly compact structure, representing an inactive closed conformation. By contrast, adding RNA induced a significant conformational change in the ZmRDR2 Head domain that opened the RNA binding tunnel, suggesting this is an active elongation conformation of ZmRDR2. Overall, our structural studies trapped both the active and inactive conformations of ZmRDR2, providing insights into the molecular mechanism of dsRNA synthesis during plant siRNA production. |
External links | Plant Cell / PubMed:35188193 / PubMed Central |
Methods | EM (single particle) / X-ray diffraction |
Resolution | 3.1 - 3.5 Å |
Structure data | EMDB-32351, PDB-7w84: EMDB-32353, PDB-7w88: PDB-7w82: |
Source |
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Keywords | PLANT PROTEIN / RDR2 / RdDM / RNA polymerase |