Browse
Submit Data
Databases
API
Help

Dataset Information

30 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Poly(A) tail recognition by a viral RNA element through assembly of a triple helix.

ABSTRACT: Kaposi's sarcoma-associated herpesvirus produces a highly abundant, nuclear noncoding RNA, polyadenylated nuclear (PAN) RNA, which contains an element that prevents its decay. The 79-nucleotide expression and nuclear retention element (ENE) was proposed to adopt a secondary structure like that of a box H/ACA small nucleolar RNA (snoRNA), with a U-rich internal loop that hybridizes to and protects the PAN RNA poly(A) tail. The crystal structure of a complex between the 40-nucleotide ENE core and oligo(A)(9) RNA at 2.5 angstrom resolution reveals that unlike snoRNAs, the U-rich loop of the ENE engages its target through formation of a major-groove triple helix. A-minor interactions extend the binding interface. Deadenylation assays confirm the functional importance of the triple helix. Thus, the ENE acts as an intramolecular RNA clamp, sequestering the PAN poly(A) tail and preventing the initiation of RNA decay.

SUBMITTER: Mitton-Fry RM

PROVIDER: S-EPMC3074936 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Poly(A) tail recognition by a viral RNA element through assembly of a triple helix.

Mitton-Fry Rachel M RM DeGregorio Suzanne J SJ Wang Jimin J Steitz Thomas A TA Steitz Joan A JA

Science (New York, N.Y.) 20101101 6008

Kaposi's sarcoma-associated herpesvirus produces a highly abundant, nuclear noncoding RNA, polyadenylated nuclear (PAN) RNA, which contains an element that prevents its decay. The 79-nucleotide expression and nuclear retention element (ENE) was proposed to adopt a secondary structure like that of a box H/ACA small nucleolar RNA (snoRNA), with a U-rich internal loop that hybridizes to and protects the PAN RNA poly(A) tail. The crystal structure of a complex between the 40-nucleotide ENE core and ...[more]

PMID: 21109672

Similar Datasets

A viral RNA structural element alters host recognition of nonself RNA.

Project description:Although interferon (IFN) signaling induces genes that limit viral infection, many pathogenic viruses overcome this host response. As an example, 2'-O methylation of the 5' cap of viral RNA subverts mammalian antiviral responses by evading restriction of Ifit1, an IFN-stimulated gene that regulates protein synthesis. However, alphaviruses replicate efficiently in cells expressing Ifit1 even though their genomic RNA has a 5' cap lacking 2'-O methylation. We show that pathogenic alphaviruses use secondary structural motifs within the 5' untranslated region (UTR) of their RNA to alter Ifit1 binding and function. Mutations within the 5'-UTR affecting RNA structural elements enabled restriction by or antagonism of Ifit1 in vitro and in vivo. These results identify an evasion mechanism by which viruses use RNA structural motifs to avoid immune restriction.

| S-EPMC4209899 | biostudies-literature

DNA recognition for virus assembly through multiple sequence-independent interactions with a helix-turn-helix motif.

Project description:The helix-turn-helix (HTH) motif features frequently in protein DNA-binding assemblies. Viral pac site-targeting small terminase proteins possess an unusual architecture in which the HTH motifs are displayed in a ring, distinct from the classical HTH dimer. Here we investigate how such a circular array of HTH motifs enables specific recognition of the viral genome for initiation of DNA packaging during virus assembly. We found, by surface plasmon resonance and analytical ultracentrifugation, that individual HTH motifs of the Bacillus phage SF6 small terminase bind the packaging regions of SF6 and related SPP1 genome weakly, with little local sequence specificity. Nuclear magnetic resonance chemical shift perturbation studies with an arbitrary single-site substrate suggest that the HTH motif contacts DNA similarly to how certain HTH proteins contact DNA non-specifically. Our observations support a model where specificity is generated through conformational selection of an intrinsically bent DNA segment by a ring of HTHs which bind weakly but cooperatively. Such a system would enable viral gene regulation and control of the viral life cycle, with a minimal genome, conferring a major evolutionary advantage for SPP1-like viruses.

| S-EPMC4737164 | biostudies-literature

A triple helix within a pseudoknot is a conserved and essential element of telomerase RNA.

Project description:Telomerase copies a short template within its integral telomerase RNA onto eukaryotic chromosome ends, compensating for incomplete replication and degradation. Telomerase action extends the proliferative potential of cells, and thus it is implicated in cancer and aging. Nontemplate regions of telomerase RNA are also crucial for telomerase function. However, they are highly divergent in sequence among species, and their roles are largely unclear. Using in silico three-dimensional modeling, constrained by mutational analysis, we propose a three-dimensional model for a pseudoknot in telomerase RNA of the budding yeast Kluyveromyces lactis. Interestingly, this structure includes a U-A.U major-groove triple helix. We confirmed the triple-helix formation in vitro using oligoribonucleotides and showed that it is essential for telomerase function in vivo. While triplex-disrupting mutations abolished telomerase function, triple compensatory mutations that formed pH-dependent G-C.C(+) triples restored the pseudoknot structure in a pH-dependent manner and partly restored telomerase function in vivo. In addition, we identified a novel type of triple helix that is formed by G-C.U triples, which also partly restored the pseudoknot structure and function. We propose that this unusual structure, so far found only in telomerase RNA, provides an essential and conserved telomerase-specific function.

| S-EPMC1820488 | biostudies-literature

Specificity of RNA-RNA helix recognition.

Project description:Functional RNAs often form compact structures characterized by closely packed helices. Crystallographic analysis of several large RNAs revealed a prevalent interaction in which unpaired adenosine residues dock into the minor groove of a receptor helix. This A-minor motif, potentially the most important element responsible for global RNA architecture, has also been suggested to contribute to the fidelity of protein synthesis by discriminating against near-cognate tRNAs on the ribosome. The specificity of A-minor interactions is fundamental to RNA tertiary structure formation, as well as to their proposed role in translational accuracy. To investigate A-minor motif specificity, we analyzed mutations in an A-minor interaction within the Tetrahymena group I self-splicing intron. Thermodynamic and x-ray crystallographic results show that the A-minor interaction strongly prefers canonical base pairs over base mismatches in the receptor helix, enabling RNA interhelical packing through specific recognition of Watson-Crick minor groove geometry.

| S-EPMC129328 | biostudies-literature

Mutational analysis of a viral RNA element that counteracts rapid RNA decay by interaction with the polyadenylate tail.

Project description:We previously demonstrated that the Kaposi's sarcoma-associated herpesvirus polyadenylated nuclear RNA contains a 79-nt cis-acting element, the ENE, which allows intronless polyadenylated transcripts to accumulate to high nuclear levels by protecting them from rapid degradation. We proposed a model based on the predicted structure of the ENE in which a U-rich internal loop hybridizes with the 3'-polyadenylate (polyA) tail to sequester it from exonucleolytic attack. We have tested this model by mutational analysis of the ENE. Point mutations in the predicted U-rich internal loop and in the flanking stems abolish the ENE's ability to (i) interact with the polyA tail, (ii) inhibit deadenylation in vitro, and (iii) stabilize transcripts in vivo. In all but one case, compensatory mutations in the flanking stems restore ENE activities, demonstrating the importance of these stems and uncovering a unique role for the loop-proximal G-C base pair in the lower stem. Increasing the U content of the U-rich internal loop surprisingly decreases stability in vivo but does not affect deadenylation in vitro, comparable to the effects of deleting certain "unstructured" regions of the ENE. Taken together, our data support the formation of the proposed ENE secondary structure in vivo and argue that the specific ENE structure inhibits rapid RNA decay in cis by engaging in a limited set of base-pairing interactions with the polyA tail.

| S-EPMC1965527 | biostudies-literature

Conservation of a triple-helix-forming RNA stability element in noncoding and genomic RNAs of diverse viruses.

Project description:Abundant expression of the long noncoding (lnc) PAN (polyadenylated nuclear) RNA by the human oncogenic gammaherpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) depends on a cis-element called the expression and nuclear retention element (ENE). The ENE upregulates PAN RNA by inhibiting its rapid nuclear decay through triple-helix formation with the poly(A) tail. Using structure-based bioinformatics, we identified six ENE-like elements in evolutionarily diverse viral genomes. Five are in double-stranded DNA viruses, including mammalian herpesviruses, insect polydnaviruses, and a protist mimivirus. One is in an insect picorna-like positive-strand RNA virus, suggesting that the ENE can counteract cytoplasmic as well as nuclear RNA decay pathways. Functionality of four of the ENEs was demonstrated by increased accumulation of an intronless polyadenylated reporter transcript in human cells. Identification of these ENEs enabled the discovery of PAN RNA homologs in two additional gammaherpesviruses, RRV and EHV2. Our findings demonstrate that searching for structural elements can lead to rapid identification of lncRNAs.

| S-EPMC3430378 | biostudies-literature

Recognition of Poly(A) RNA through Its Intrinsic Helical Structure.

Project description:The polyadenosine (poly(A)) tail, which is found on the 3' end of almost all eukaryotic messenger RNAs (mRNAs), plays an important role in the posttranscriptional regulation of gene expression. Shortening of the poly(A) tail, a process known as deadenylation, is thought to be the first and rate-limiting step of mRNA turnover. Deadenylation is performed by the Pan2-Pan3 and Ccr4-Not complexes that contain highly conserved exonuclease enzymes Pan2, and Ccr4 and Caf1, respectively. These complexes have been extensively studied, but the mechanisms of how the deadenylase enzymes recognize the poly(A) tail were poorly understood until recently. Here, we summarize recent work from our laboratory demonstrating that the highly conserved Pan2 exonuclease recognizes the poly(A) tail, not through adenine-specific functional groups, but through the conformation of poly(A) RNA. Our biochemical, biophysical, and structural investigations suggest that poly(A) forms an intrinsic base-stacked, single-stranded helical conformation that is recognized by Pan2, and that disruption of this structure inhibits both Pan2 and Caf1. This intrinsic structure has been shown to be important in poly(A) recognition in other biological processes, further underlining the importance of the unique conformation of poly(A).

| S-EPMC7116106 | biostudies-literature

Polyproline and triple helix motifs in host-pathogen recognition.

Project description:Secondary structure elements often mediate protein-protein interactions. Despite their low abundance in folded proteins, polyproline II (PPII) and its variant, the triple helix, are frequently involved in protein-protein interactions, likely due to their peculiar propensity to be solvent-exposed. We here review the role of PPII and triple helix in mediating hostpathogen interactions, with a particular emphasis to the structural aspects of these processes. After a brief description of the basic structural features of these elements, examples of host-pathogen interactions involving these motifs are illustrated. Literature data suggest that the role played by PPII motif in these processes is twofold. Indeed, PPII regions may directly mediate interactions between proteins of the host and the pathogen. Alternatively, PPII may act as structural spacers needed for the correct positioning of the elements needed for adhesion and infectivity. Recent investigations have highlighted that collagen triple helix is also a common target for bacterial adhesins. Although structural data on complexes between adhesins and collagen models are rather limited, experimental and theoretical studies have unveiled some interesting clues of the recognition process. Interestingly, very recent data show that not only is the triple helix used by pathogens as a target in the host-pathogen interaction but it may also act as a bait in these processes since bacterial proteins containing triple helix regions have been shown to interact with host proteins. As both PPII and triple helix expose several main chain non-satisfied hydrogen bond acceptors and donors, both elements are highly solvated. The preservation of the solvation state of both PPII and triple helix upon protein-protein interaction is an emerging aspect that will be here thoroughly discussed.

| S-EPMC3707005 | biostudies-literature

New aspects of the interaction of the antibiotic coralyne with RNA: coralyne induces triple helix formation in poly(rA)*poly(rU).

Project description:The interaction of coralyne with poly(A)*poly(U), poly(A)*2poly(U), poly(A) and poly(A)*poly(A) is analysed using spectrophotometric, spectrofluorometric, circular dichroism (CD), viscometric, stopped-flow and temperature-jump techniques. It is shown for the first time that coralyne induces disproportionation of poly(A)*poly(U) to triplex poly(A)*2poly(U) and single-stranded poly(A) under suitable values of the [dye]/[polymer] ratio (C(D)/C(P)). Kinetic, CD and spectrofluorometric experiments reveal that this process requires that coralyne (D) binds to duplex. The resulting complex (AUD) reacts with free duplex giving triplex (UAUD) and free poly(A); moreover, ligand exchange between duplex and triplex occurs. A reaction mechanism is proposed and the reaction parameters are evaluated. For C(D)/C(P)> 0.8 poly(A)*poly(U) does not disproportionate at 25 degrees C and dye intercalation into AU to give AUD is the only observed process. Melting experiments as well show that coralyne induces the duplex disproportionation. Effects of temperature, ionic strength and ethanol content are investigated. One concludes that triplex formation requires coralyne be only partially intercalated into AUD. Under suitable concentration conditions, this feature favours the interaction of free AU with AUD to give the AUDAU intermediate which evolves into triplex UAUD and single-stranded poly(A). Duplex poly(A)*poly(A) undergoes aggregation as well, but only at much higher polymer concentrations compared to poly(A)*poly(U).

| S-EPMC2836573 | biostudies-literature

DNA triple-helix formation on nucleosome-bound poly(dA).poly(dT) tracts.

Project description:We have used DNase I and hydroxyl-radical footprinting to examine the formation of intermolecular DNA triple helices on nucleosome-bound DNA fragments containing An.Tn tracts. We found that it is possible to form triplexes on these nucleosome-bound DNAs, but the stability of the complexes depends on the orientation of the A tract with respect to the protein surface. Hydroxyl-radical cleavage of these complexes suggests that the DNA fragments are still associated with the nucleosome. However, the phased cleavage pattern is lost in the vicinity of the triplex, suggesting that the DNA has locally moved away from the protein surface.

| S-EPMC1219581 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data