5zak

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Cryo-EM structure of human Dicer and its complexes with a pre-miRNA substrate

Structural highlights

5zak is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:Electron Microscopy, Resolution 4.4Å
Experimental data:Check to display Experimental Data
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

TRBP2_HUMAN Required for formation of the RNA induced silencing complex (RISC). Component of the RISC loading complex (RLC), also known as the micro-RNA (miRNA) loading complex (miRLC), which is composed of DICER1, EIF2C2/AGO2 and TARBP2. Within the RLC/miRLC, DICER1 and TARBP2 are required to process precursor miRNAs (pre-miRNAs) to mature miRNAs and then load them onto EIF2C2/AGO2. EIF2C2/AGO2 bound to the mature miRNA constitutes the minimal RISC and may subsequently dissociate from DICER1 and TARBP2. May also play a role in the production of short interfering RNAs (siRNAs) from double-stranded RNA (dsRNA) by DICER1. Binds to the HIV-1 TAR RNA which is located in the long terminal repeat (LTR) of HIV-1, and stimulates translation of TAR-containing RNAs. This is achieved in part at least by binding to and inhibiting EIF2AK2/PKR, thereby reducing phosphorylation and inhibition of EIF2S1/eIF-2-alpha. May also promote translation of TAR-containing RNAs independently of EIF2AK2/PKR.[1] [2] [3] [4] [5] [6] [7] [8] [9]

Publication Abstract from PubMed

Human Dicer (hDicer) is a multi-domain protein belonging to the RNase III family. It plays pivotal roles in small RNA biogenesis during the RNA interference (RNAi) pathway by processing a diverse range of double-stranded RNA (dsRNA) precursors to generate approximately 22 nt microRNA (miRNA) or small interfering RNA (siRNA) products for sequence-directed gene silencing. In this work, we solved the cryoelectron microscopy (cryo-EM) structure of hDicer in complex with its cofactor protein TRBP and revealed the precise spatial arrangement of hDicer's multiple domains. We further solved structures of the hDicer-TRBP complex bound with pre-let-7 RNA in two distinct conformations. In combination with biochemical analysis, these structures reveal a property of the hDicer-TRBP complex to promote the stability of pre-miRNA's stem duplex in a pre-dicing state. These results provide insights into the mechanism of RNA processing by hDicer and illustrate the regulatory role of hDicer's N-terminal helicase domain.

Cryo-EM Structure of Human Dicer and Its Complexes with a Pre-miRNA Substrate.,Liu Z, Wang J, Cheng H, Ke X, Sun L, Zhang QC, Wang HW Cell. 2018 May 17;173(5):1191-1203.e12. doi: 10.1016/j.cell.2018.03.080. Epub, 2018 Apr 26. PMID:29706542[10]

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

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See Also

References

  1. Dorin D, Bonnet MC, Bannwarth S, Gatignol A, Meurs EF, Vaquero C. The TAR RNA-binding protein, TRBP, stimulates the expression of TAR-containing RNAs in vitro and in vivo independently of its ability to inhibit the dsRNA-dependent kinase PKR. J Biol Chem. 2003 Feb 14;278(7):4440-8. Epub 2002 Dec 9. PMID:12475984 doi:10.1074/jbc.M208954200
  2. Gregory RI, Chendrimada TP, Cooch N, Shiekhattar R. Human RISC couples microRNA biogenesis and posttranscriptional gene silencing. Cell. 2005 Nov 18;123(4):631-40. Epub 2005 Nov 3. PMID:16271387 doi:10.1016/j.cell.2005.10.022
  3. Haase AD, Jaskiewicz L, Zhang H, Laine S, Sack R, Gatignol A, Filipowicz W. TRBP, a regulator of cellular PKR and HIV-1 virus expression, interacts with Dicer and functions in RNA silencing. EMBO Rep. 2005 Oct;6(10):961-7. PMID:16142218 doi:10.1038/sj.embor.7400509
  4. Maniataki E, Mourelatos Z. A human, ATP-independent, RISC assembly machine fueled by pre-miRNA. Genes Dev. 2005 Dec 15;19(24):2979-90. PMID:16357216 doi:10.1101/gad.1384005
  5. Chendrimada TP, Gregory RI, Kumaraswamy E, Norman J, Cooch N, Nishikura K, Shiekhattar R. TRBP recruits the Dicer complex to Ago2 for microRNA processing and gene silencing. Nature. 2005 Aug 4;436(7051):740-4. Epub 2005 Jun 22. PMID:15973356 doi:10.1038/nature03868
  6. Lee Y, Hur I, Park SY, Kim YK, Suh MR, Kim VN. The role of PACT in the RNA silencing pathway. EMBO J. 2006 Feb 8;25(3):522-32. Epub 2006 Jan 19. PMID:16424907 doi:10.1038/sj.emboj.7600942
  7. Kok KH, Ng MH, Ching YP, Jin DY. Human TRBP and PACT directly interact with each other and associate with dicer to facilitate the production of small interfering RNA. J Biol Chem. 2007 Jun 15;282(24):17649-57. Epub 2007 Apr 23. PMID:17452327 doi:10.1074/jbc.M611768200
  8. MacRae IJ, Ma E, Zhou M, Robinson CV, Doudna JA. In vitro reconstitution of the human RISC-loading complex. Proc Natl Acad Sci U S A. 2008 Jan 15;105(2):512-7. doi: 10.1073/pnas.0710869105., Epub 2008 Jan 4. PMID:18178619 doi:10.1073/pnas.0710869105
  9. Melo SA, Ropero S, Moutinho C, Aaltonen LA, Yamamoto H, Calin GA, Rossi S, Fernandez AF, Carneiro F, Oliveira C, Ferreira B, Liu CG, Villanueva A, Capella G, Schwartz S Jr, Shiekhattar R, Esteller M. A TARBP2 mutation in human cancer impairs microRNA processing and DICER1 function. Nat Genet. 2009 Mar;41(3):365-70. doi: 10.1038/ng.317. Epub 2009 Feb 15. PMID:19219043 doi:10.1038/ng.317
  10. Liu Z, Wang J, Cheng H, Ke X, Sun L, Zhang QC, Wang HW. Cryo-EM Structure of Human Dicer and Its Complexes with a Pre-miRNA Substrate. Cell. 2018 May 17;173(5):1191-1203.e12. doi: 10.1016/j.cell.2018.03.080. Epub, 2018 Apr 26. PMID:29706542 doi:http://dx.doi.org/10.1016/j.cell.2018.03.080

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5zak, resolution 4.40Å

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