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3adl

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Structure of TRBP2 and its molecule implications for miRNA processing

Structural highlights

3adl is a 3 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:	X-ray diffraction, Resolution 2.2Å
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]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The Arabidopsis HYPONASTIC LEAVES1 (HYL1) is a double-stranded RNA-binding protein that forms a complex with DICER-LIKE1 (DCL1) and SERRATE to facilitate processing of primary miRNAs into microRNAs (miRNAs). However, the structural mechanisms of miRNA maturation by this complex are poorly understood. Here, we present the crystal structures of double-stranded RNA binding domains (dsRBD1 and dsRBD2) of HYL1 and HYL1 dsRBD1 (HR1)/dsRNA complex as well as human TRBP2 dsRBD2 (TR2)/dsRNA complex for comparison analysis. Structural and functional study demonstrates that both HR1 and TR2 are canonical dsRBDs for dsRNA binding, whereas HR2 of HYL1 is a non-canonical dsRBD harboring a putative dimerization interface. Domain swapping within the context of HYL1 demonstrates that TR2 can supplant the function of HR1 in vitro and in vivo. Further biochemical analyses suggest that HYL1 probably binds to the miRNA/miRNA( *) region of precursors as a dimer mediated by HR2.

Structure of arabidopsis HYPONASTIC LEAVES1 and its molecular implications for miRNA processing.,Yang SW, Chen HY, Yang J, Machida S, Chua NH, Yuan YA Structure. 2010 May 12;18(5):594-605. PMID:20462493^[10]

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

References

↑ 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
↑ 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
↑ 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
↑ 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
↑ 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
↑ 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
↑ 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
↑ 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
↑ 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
↑ Yang SW, Chen HY, Yang J, Machida S, Chua NH, Yuan YA. Structure of arabidopsis HYPONASTIC LEAVES1 and its molecular implications for miRNA processing. Structure. 2010 May 12;18(5):594-605. PMID:20462493 doi:10.1016/j.str.2010.02.006