scholarly journals Recovery of Infectivity from cDNA Clones of Nodamura Virus and Identification of Small Nonstructural Proteins

Virology ◽  
2003 ◽  
Vol 305 (2) ◽  
pp. 436-451 ◽  
Author(s):  
Kyle L. Johnson ◽  
B.Duane Price ◽  
L.Andrew Ball
Keyword(s):  
Cdna Clones ◽  
Nonstructural Proteins ◽  
Nodamura Virus

scholarly journals Nodamura Virus Nonstructural Protein B2 Can Enhance Viral RNA Accumulation in both Mammalian and Insect Cells

2004 ◽  
Vol 78 (12) ◽  
pp. 6698-6704 ◽  
Author(s):  
Kyle L. Johnson ◽  
B. Duane Price ◽  
Lance D. Eckerle ◽  
L. Andrew Ball
Keyword(s):  
Rna Interference ◽  
Cell Lines ◽  
Nonstructural Protein ◽  
Viral Rna ◽  
Host Cells ◽  
Flock House Virus ◽  
Nonstructural Proteins ◽  
Reading Frame ◽  
Rna Accumulation ◽  
Nodamura Virus

ABSTRACT During infection of both vertebrate and invertebrate cell lines, the alphanodavirus Nodamura virus (NoV) expresses two nonstructural proteins of different lengths from the B2 open reading frame. The functions of these proteins have yet to be determined, but B2 of the related Flock House virus suppresses RNA interference both in Drosophila cells and in transgenic plants. To examine whether the NoV B2 proteins had similar functions, we compared the replication of wild-type NoV RNA with that of mutants unable to make the B2 proteins. We observed a defect in the accumulation of mutant viral RNA that varied in extent from negligible in some cell lines (e.g., baby hamster kidney cells) to severe in others (e.g., human HeLa and Drosophila DL-1 cells). These results are consistent with the notion that the NoV B2 proteins act to circumvent an innate antiviral response such as RNA interference that differs in efficacy among different host cells.

Design and in-silico screening of Peptide Nucleic Acid (PNA) inspired novel pronucleotide scaffolds targeting COVID-19

2020 ◽  
Vol 16 ◽  
Author(s):  
Bichismita Sahu ◽  
Santosh Kumar Behera ◽  
Rudradip Das ◽  
Tanay Dalvi ◽  
Arnab Chowdhury ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
In Silico ◽  
Peptide Nucleic Acid ◽  
Large Set ◽  
Nonstructural Proteins ◽  
In Silico Screening ◽  
Replication Process ◽  
Enveloped Virus ◽  
Treatment Regimens ◽  
Novel Coronavirus

Introduction: The outburst of the novel coronavirus COVID-19, at the end of December 2019 has turned itself into a pandemic taking a heavy toll on human lives. The causal agent being SARS-CoV-2, a member of the long-known Coronaviridae family, is a positive sense single-stranded enveloped virus and quite closely related to SARS-CoV. It has become the need of the hour to understand the pathophysiology of this disease, so that drugs, vaccines, treatment regimens and plausible therapeutic agents can be produced. Methods: In this regard, recent studies uncovered the fact that the viral genome of SARS-CoV-2 encodes nonstructural proteins like RNA dependent RNA polymerase (RdRp) which is an important tool for its transcription and replication process. A large number of nucleic acid based anti-viral drugs are being repurposed for treating COVID-19 targeting RdRp. Few of them are in the advanced stage of clinical trials including Remdesivir. While performing close investigation of the large set of nucleic acid based drugs, we were surprised to find that the synthetic nucleic acid backbone is explored very little or rare. Results: We have designed scaffolds derived from peptide nucleic acid (PNA) and subjected them for in-silico screening systematically. These designed molecules have demonstrated excellent binding towards RdRp. Compound 12 was found to possess similar binding affinity as Remdesivir with comparable pharmacokinetics. However, the in-silico toxicity prediction indicates compound 12 may be a superior molecule which can be explored further due to its excellent safety-profile with LD50 (12,000mg/kg) as opposed to Remdesivir (LD50 =1000mg/kg). Conclusion: Compound 12 falls in the safe category of class 6. Synthetic feasibility, equipotent binding and very low toxicity of this peptide nucleic acid derived compounds can serve as a leading scaffold to design, synthesize and evaluate many of similar compounds for the treatment of COVID-19.

Structural and nonstructural proteins of a rabbit parvovirus.

1983 ◽  
Vol 45 (2) ◽  
pp. 627-633 ◽  
Author(s):  
Y Matsunaga ◽  
S Matsuno
Keyword(s):  
Nonstructural Proteins

scholarly journals Structure and Function of Major SARS-CoV-2 and SARS-CoV Proteins

2021 ◽  
Vol 15 ◽  
pp. 117793222110258
Author(s):  
Ritesh Gorkhali ◽  
Prashanna Koirala ◽  
Sadikshya Rijal ◽  
Ashmita Mainali ◽  
Adesh Baral ◽  
...  
Keyword(s):  
Genomic Organization ◽  
Membrane Vesicles ◽  
Structural Proteins ◽  
Host Immune System ◽  
Accessory Proteins ◽  
Nonstructural Proteins ◽  
N Protein ◽  
Small Proteins ◽  
Methylation Mark ◽  
And Function

SARS-CoV-2 virus, the causative agent of COVID-19 pandemic, has a genomic organization consisting of 16 nonstructural proteins (nsps), 4 structural proteins, and 9 accessory proteins. Relative of SARS-CoV-2, SARS-CoV, has genomic organization, which is very similar. In this article, the function and structure of the proteins of SARS-CoV-2 and SARS-CoV are described in great detail. The nsps are expressed as a single or two polyproteins, which are then cleaved into individual proteins using two proteases of the virus, a chymotrypsin-like protease and a papain-like protease. The released proteins serve as centers of virus replication and transcription. Some of these nsps modulate the host’s translation and immune systems, while others help the virus evade the host immune system. Some of the nsps help form replication-transcription complex at double-membrane vesicles. Others, including one RNA-dependent RNA polymerase and one exonuclease, help in the polymerization of newly synthesized RNA of the virus and help minimize the mutation rate by proofreading. After synthesis of the viral RNA, it gets capped. The capping consists of adding GMP and a methylation mark, called cap 0 and additionally adding a methyl group to the terminal ribose called cap1. Capping is accomplished with the help of a helicase, which also helps remove a phosphate, two methyltransferases, and a scaffolding factor. Among the structural proteins, S protein forms the receptor of the virus, which latches on the angiotensin-converting enzyme 2 receptor of the host and N protein binds and protects the genomic RNA of the virus. The accessory proteins found in these viruses are small proteins with immune modulatory roles. Besides functions of these proteins, solved X-ray and cryogenic electron microscopy structures related to the function of the proteins along with comparisons to other coronavirus homologs have been described in the article. Finally, the rate of mutation of SARS-CoV-2 residues of the proteome during the 2020 pandemic has been described. Some proteins are mutated more often than other proteins, but the significance of these mutation rates is not fully understood.

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