scholarly journals The Cap-Snatching SFTSV Endonuclease Domain Is an Antiviral Target

Cell Reports ◽  
2020 ◽  
Vol 30 (1) ◽  
pp. 153-163.e5 ◽  
Author(s):  
Wenjie Wang ◽  
Woo-Jin Shin ◽  
Bojie Zhang ◽  
Younho Choi ◽  
Ji-Seung Yoo ◽  
...  
Keyword(s):  
Endonuclease Domain

scholarly journals Temperature-Sensitive Mutants in the Influenza A Virus RNA Polymerase: Alterations in the PA Linker Reduce Nuclear Targeting of the PB1-PA Dimer and Result in Viral Attenuation

2015 ◽  
Vol 89 (12) ◽  
pp. 6376-6390 ◽  
Author(s):  
Bruno Da Costa ◽  
Alix Sausset ◽  
Sandie Munier ◽  
Alexandre Ghounaris ◽  
Nadia Naffakh ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Rna Polymerase ◽  
Nuclear Import ◽  
Influenza A ◽  
Rational Design ◽  
Hot Spot ◽  
Temperature Sensitive ◽  
Nuclear Targeting ◽  
Virus Rna ◽  
Endonuclease Domain

ABSTRACTThe influenza virus RNA-dependent RNA polymerase catalyzes genome replication and transcription within the cell nucleus. Efficient nuclear import and assembly of the polymerase subunits PB1, PB2, and PA are critical steps in the virus life cycle. We investigated the structure and function of the PA linker (residues 197 to 256), located between its N-terminal endonuclease domain and its C-terminal structured domain that binds PB1, the polymerase core. Circular dichroism experiments revealed that the PA linker by itself is structurally disordered. A large series of PA linker mutants exhibited a temperature-sensitive (ts) phenotype (reduced viral growth at 39.5°C versus 37°C/33°C), suggesting an alteration of folding kinetic parameters. Thetsphenotype was associated with a reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using a fluorescent-tagged PB1, we observed thattsand lethal PA mutants did not efficiently recruit PB1 to reach the nucleus at 39.5°C. A protein complementation assay using PA mutants, PB1, and β-importin IPO5 tagged with fragments of theGaussia princepsluciferase showed that increasing the temperature negatively modulated the PA-PB1 and the PA-PB1-IPO5 interactions or complex stability. The selection of revertant viruses allowed the identification of different types of compensatory mutations located in one or the other of the three polymerase subunits. Twotsmutants were shown to be attenuated and able to induce antibodies in mice. Taken together, our results identify a PA domain critical for PB1-PA nuclear import and that is a “hot spot” to engineertsmutants that could be used to design novel attenuated vaccines.IMPORTANCEBy targeting a discrete domain of the PA polymerase subunit of influenza virus, we were able to identify a series of 9 amino acid positions that are appropriate to engineer temperature-sensitive (ts) mutants. This is the first time that a large number oftsmutations were engineered in such a short domain, demonstrating that rational design oftsmutants can be achieved. We were able to associate this phenotype with a defect of transport of the PA-PB1 complex into the nucleus. Reversion substitutions restored the ability of the complex to move to the nucleus. Two of thesetsmutants were shown to be attenuated and able to produce antibodies in mice. These results are of high interest for the design of novel attenuated vaccines and to develop new antiviral drugs.

scholarly journals Destabilization of the Colicin E9 Endonuclease Domain by Interaction with Negatively Charged Phospholipids

2004 ◽  
Vol 279 (21) ◽  
pp. 22145-22151 ◽  
Author(s):  
Khédidja Mosbahi ◽  
Daniel Walker ◽  
Edward Lea ◽  
Geoffrey R. Moore ◽  
Richard James ◽  
...  
Keyword(s):  
Endonuclease Domain ◽  
Colicin E9

scholarly journals The Endonuclease Domain of Bacteriophage Terminases Belongs to the Resolvase/Integrase/Ribonuclease H Superfamily

2005 ◽  
Vol 281 (9) ◽  
pp. 5829-5836 ◽  
Author(s):  
Luc Ponchon ◽  
Pascale Boulanger ◽  
Gilles Labesse ◽  
Lucienne Letellier
Keyword(s):  
Ribonuclease H ◽  
Endonuclease Domain

scholarly journals Endonuclease domain of non-LTR retrotransposons: loss-of-function mutants and modeling of the R2Bm endonuclease

2016 ◽  
Vol 44 (7) ◽  
pp. 3276-3287 ◽  
Author(s):  
Aruna Govindaraju ◽  
Jeremy D. Cortez ◽  
Brad Reveal ◽  
Shawn M. Christensen
Keyword(s):  
Ltr Retrotransposons ◽  
Loss Of Function ◽  
Endonuclease Domain

scholarly journals The endonuclease domain of MutL interacts with the β sliding clamp

DNA Repair ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Monica C. Pillon ◽  
Jeffrey H. Miller ◽  
Alba Guarné
Keyword(s):  
Sliding Clamp ◽  
Endonuclease Domain

scholarly journals A mutation in the endonuclease domain of mouse MLH3 reveals novel roles for MutLγ during crossover formation in meiotic prophase I

PLoS Genetics ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. e1008177 ◽  
Author(s):  
Melissa Toledo ◽  
Xianfei Sun ◽  
Miguel A. Brieño-Enríquez ◽  
Vandana Raghavan ◽  
Stephen Gray ◽  
...  
Keyword(s):  
Meiotic Prophase ◽  
Prophase I ◽  
Meiotic Prophase I ◽  
Endonuclease Domain

scholarly journals Enhanced efficacy of endonuclease inhibitor baloxavir acid against orthobunyaviruses when used in combination with ribavirin

2020 ◽  
Vol 75 (11) ◽  
pp. 3189-3193
Author(s):  
Sebastiaan ter Horst ◽  
Yaiza Fernandez-Garcia ◽  
Marcella Bassetto ◽  
Stephan Günther ◽  
Andrea Brancale ◽  
...  
Keyword(s):  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Docking Simulation ◽  
Antiviral Effect ◽  
Inhibitory Effect ◽  
Surface Model ◽  
La Crosse Virus ◽  
Endonuclease Domain ◽  
Substrate Cleavage

Abstract Objectives Baloxavir acid is an endonuclease inhibitor approved for use against influenza. We evaluated whether this compound also targets the endonuclease domain of orthobunyaviruses and therefore could potentially be used against orthobunyavirus infections. Methods We performed a thermal shift assay and a fluorescence resonance energy transfer (FRET)-based nuclease monitoring assay using the La Crosse virus (LACV) endonuclease and baloxavir acid to prove their interaction and identify an inhibitory effect. Their interaction was further studied in a docking simulation using Glide SP. We show that baloxavir acid inhibits the viral replication of Bunyamwera virus (BUNV)–mCherry in vitro using high-content imaging and virus yield assay. Lastly, we investigated the use of baloxavir acid in combination with ribavirin in vitro by implementing the Zero Interaction Potency response surface model. Results We show that baloxavir acid augments LACV enzyme’s melting temperature with ΔTm 9.5 ± 0.4°C and inhibited substrate cleavage with IC50 0.39 ± 0.03 μM. Moreover, our docking simulation suggests that baloxavir acid is able to establish an efficient binding with the LACV endonuclease. In the cell-based assay, we observed that baloxavir acid and ribavirin inhibited BUNV–mCherry with an EC50 of 0.7 ± 0.2 μM and 26.6 ± 8.9 μM, respectively. When used in combination, we found a maximum synergistic effect of 8.64. Conclusions The influenza endonuclease inhibitor baloxavir acid is able to bind to and interfere with the endonuclease domain of orthobunyaviruses and yields a more potent antiviral effect than ribavirin against BUNV–mCherry. The combination of both compounds results in a more potent antiviral effect, suggesting that these molecules could potentially be combined to treat orthobunyavirus-infected patients.

Magnesium-Dependent RNA Binding to the PA Endonuclease Domain of the Avian Influenza Polymerase

2014 ◽  
Vol 118 (4) ◽  
pp. 873-889 ◽  
Author(s):  
Shiyan Xiao ◽  
Michael L. Klein ◽  
David N. LeBard ◽  
Benjamin G. Levine ◽  
Haojun Liang ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Rna Binding ◽  
Endonuclease Domain ◽  
Influenza Polymerase

scholarly journals Algal Viruses with Distinct Intraspecies Host Specificities Include Identical Intein Elements

2005 ◽  
Vol 71 (7) ◽  
pp. 3599-3607 ◽  
Author(s):  
Keizo Nagasaki ◽  
Yoko Shirai ◽  
Yuji Tomaru ◽  
Kensho Nishida ◽  
Shmuel Pietrokovski
Keyword(s):  
Dna Polymerase ◽  
Homing Endonuclease ◽  
Sister Group ◽  
Dna Virus ◽  
Single Nucleotide Change ◽  
Double Stranded Dna ◽  
Endonuclease Domain ◽  
Algal Viruses ◽  
Molecular Phylogenetic ◽  
Position Coding

ABSTRACT Heterosigma akashiwo virus (HaV) is a large double-stranded DNA virus infecting the single-cell bloom-forming raphidophyte (golden brown alga) H. akashiwo. A molecular phylogenetic sequence analysis of HaV DNA polymerase showed that it forms a sister group with Phycodnaviridae algal viruses. All 10 examined HaV strains, which had distinct intraspecies host specificities, included an intein (protein intron) in their DNA polymerase genes. The 232-amino-acid inteins differed from each other by no more than a single nucleotide change. All inteins were present at the same conserved position, coding for an active-site motif, which also includes inteins in mimivirus (a very large double-stranded DNA virus of amoebae) and in several archaeal DNA polymerase genes. The HaV intein is closely related to the mimivirus intein, and both are apparently monophyletic to the archaeal inteins. These observations suggest the occurrence of horizontal transfers of inteins between viruses of different families and between archaea and viruses and reveal that viruses might be reservoirs and intermediates in horizontal transmissions of inteins. The homing endonuclease domain of the HaV intein alleles is mostly deleted. The mechanism keeping their sequences basically identical in HaV strains specific for different hosts is yet unknown. One possibility is that rapid and local changes in the HaV genome change its host specificity. This is the first report of inteins found in viruses infecting eukaryotic algae.

scholarly journals Cross-Protection of Influenza A Virus Infection by a DNA Aptamer Targeting the PA Endonuclease Domain

2015 ◽  
Vol 59 (7) ◽  
pp. 4082-4093 ◽  
Author(s):  
Shuofeng Yuan ◽  
Naru Zhang ◽  
Kailash Singh ◽  
Huiping Shuai ◽  
Hin Chu ◽  
...  
Keyword(s):  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
H5n1 Virus ◽  
Influenza Viruses ◽  
Cross Protection ◽  
Dna Aptamer ◽  
Endonuclease Activity ◽  
Endonuclease Domain

ABSTRACTAmino acid residues in the N-terminal of the PA subunit (PAN) of the influenza A virus polymerase play critical roles in endonuclease activity, protein stability, and viral RNA (vRNA) promoter binding. In addition, PANis highly conserved among different subtypes of influenza virus, which suggests PANto be a desired target in the development of anti-influenza agents. We selected DNA aptamers targeting the intact PA protein or the PANdomain of an H5N1 virus strain using systematic evolution of ligands by exponential enrichment (SELEX). The binding affinities of selected aptamers were measured, followed by an evaluation ofin vitroendonuclease inhibitory activity. Next, the antiviral effects of enriched aptamers against influenza A virus infections were examined. A total of three aptamers targeting PA and six aptamers targeting PANwere selected. Our data demonstrated that all three PA-selected aptamers neither inhibited endonuclease activity nor exhibited antiviral efficacy, whereas four of the six PAN-selected aptamers inhibited both endonuclease activity and H5N1 virus infection. Among the four effective aptamers, one exhibited cross-protection against infections of H1N1, H5N1, H7N7, and H7N9 influenza viruses, with a 50% inhibitory concentration (IC50) of around 10 nM. Notably, this aptamer was identified at the 5th round but disappeared after the 10th round of selection, suggesting that the identification and evaluation of aptamers at early rounds of selection may be highly helpful for screening effective aptamers. Overall, our study provides novel insights for screening and developing effective aptamers for use as anti-influenza drugs.

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