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-Structure paper
Title | Cryo-EM structure of SMG1-SMG8-SMG9 complex. |
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Journal, issue, pages | Cell Res, Vol. 29, Issue 12, Page 1027-1034, Year 2019 |
Publish date | Nov 15, 2019 |
Authors | Li Zhu / Liang Li / Yilun Qi / Zishuo Yu / Yanhui Xu / |
PubMed Abstract | Nonsense-mediated mRNA decay (NMD) targets premature stop codon (PTC)-containing mRNAs for rapid degradation, and is essential for mammalian embryonic development, brain development and modulation of ...Nonsense-mediated mRNA decay (NMD) targets premature stop codon (PTC)-containing mRNAs for rapid degradation, and is essential for mammalian embryonic development, brain development and modulation of the stress response. The key event in NMD is the SMG1-mediated phosphorylation of an RNA helicase UPF1 and SMG1 kinase activity is inhibited by SMG8 and SMG9 in an unknown mechanism. Here, we determined the cryo-EM structures of human SMG1 at 3.6 Å resolution and the SMG1-SMG8-SMG9 complex at 3.4 Å resolution, respectively. SMG8 has a C-terminal kinase inhibitory domain (KID), which covers the catalytic pocket and inhibits the kinase activity of SMG1. Structural analyses suggest that GTP hydrolysis of SMG9 would lead to a dramatic conformational change of SMG8-SMG9 and the KID would move away from the inhibitory position to restore SMG1 kinase activity. Thus, our structural and biochemical analyses provide a mechanistic understanding of SMG1-SMG8-SMG9 complex assembly and the regulatory mechanism of SMG1 kinase activity. |
External links | Cell Res / PubMed:31729466 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.43 - 3.63 Å |
Structure data | |
Chemicals | ChemComp-GTP: ChemComp-MG: |
Source |
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Keywords | TRANSFERASE / SMG1 / Cryo-EM / Nonsense-mediated mRNA decay / TRANSFERASE/TRANSCRIPTION / SMG189 / TRANSFERASE-TRANSCRIPTION complex |