scholarly journals Reverse genetic characterization of the natural genomic deletion in SARS-Coronavirus strain Frankfurt-1 open reading frame 7b reveals an attenuating function of the 7b protein in-vitro and in-vivo

2009 ◽  
Vol 6 (1) ◽  
pp. 131 ◽  
Author(s):  
Susanne Pfefferle ◽  
Verena Krähling ◽  
Vanessa Ditt ◽  
Klaus Grywna ◽  
Elke Mühlberger ◽  
...  
Keyword(s):  
Genetic Characterization ◽  
Open Reading Frame ◽  
Reverse Genetic ◽  
Sars Coronavirus ◽  
Genomic Deletion ◽  
Reading Frame

scholarly journals Murine cytomegalovirus open reading frame m29.1 augments virus replication both in vitro and in vivo

2007 ◽  
Vol 88 (11) ◽  
pp. 2941-2951 ◽  
Author(s):  
Mohammad M. Ahasan ◽  
Clive Sweet
Keyword(s):  
Virus Replication ◽  
Post Infection ◽  
Stop Codon ◽  
Premature Stop Codon ◽  
Open Reading Frame ◽  
Murine Cytomegalovirus ◽  
Reading Frame ◽  
Codon Mutation

Murine cytomegalovirus mutant Rc29, with a premature stop codon mutation in the m29 open reading frame (ORF), produced no apparent phenotype in cell culture or following infection of BALB/c mice. In contrast, a similar mutant virus, Rc29.1, with a premature stop codon mutation in its m29.1 ORF, showed reduced virus yields (2–3 log10 p.f.u. ml−1) in tissue culture. Mutant virus yields in BALB/c mice were delayed, reduced (∼1 log10 p.f.u. per tissue) and persisted less well in salivary glands compared with wild-type (wt) and revertant (Rv29.1) virus. In severe combined immunodeficiency mice, Rc29.1 virus showed delayed and reduced replication initially in all tissues (liver, spleen, kidneys, heart, lung and salivary glands). This delayed death until 31 days post-infection (p.i.) compared with wt (23 days p.i.) but at death virus yields were similar to wt. m29 gene transcription was initiated at early times post-infection, while production of a transcript from ORF m29.1 in the presence of cycloheximide indicated that it was an immediate-early gene. ORFs m29.1 and M28 are expressed from a bicistronic message, which is spliced infrequently. However, it is likely that each ORF expresses its own protein, as antiserum derived in rabbits to the m29.1 protein expressed in bacteria from the m29.1 ORF detected only one protein in Western blot analysis of the size predicted for the m29.1 protein. Our results suggest that neither ORF is essential for virus replication but m29.1 is important for optimal viral growth in vitro and in vivo.

scholarly journals Ilarviruses Encode a Cucumovirus-Like 2b Gene That Is Absent in Other Genera within the Bromoviridae

1998 ◽  
Vol 72 (8) ◽  
pp. 6956-6959 ◽  
Author(s):  
Hong-Wu Xin ◽  
Liang-Hui Ji ◽  
Simon W. Scott ◽  
Robert H. Symons ◽  
Shou-Wei Ding
Keyword(s):  
Open Reading Frame ◽  
Latent Virus ◽  
Evolutionary Origin ◽  
Protein Species ◽  
Subgenomic Rna ◽  
Reading Frame ◽  
2B Protein ◽  
Sequence Similarities

ABSTRACT We found that RNA 2 of the four ilarviruses sequenced to date encodes an additional conserved open reading frame (ORF), 2b, that overlaps the 3′ end of the previously known ORF, 2a. A novel RNA species of 851 nucleotides was found to accumulate to high levels in plants infected with spinach latent virus (SpLV). Further analysis showed that RNA 4A is a subgenomic RNA of RNA 2 and encodes all of ORF 2b. Moreover, a protein species of the size expected for SpLV ORF 2b was translated in vitro from the RNA 4A-containing virion RNAs. The data support the suggestion that the SpLV 2b protein is translated in vivo. The 2b gene of ilarviruses, which is not encoded by alfamoviruses and bromoviruses, shares several features with the previously reported cucumovirus 2b gene; however, their encoded proteins share no detectable sequence similarities. The evolutionary origin of the 2b gene is discussed.

Molecular biology and pathogenesis of hepatitis E virus

1999 ◽  
Vol 1 (18) ◽  
pp. 1-16 ◽  
Author(s):  
Shahid Jameel
Keyword(s):  
Viral Genome ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Host Interactions ◽  
Processing Enzymes ◽  
Open Reading Frame 2

Hepatitis E virus (HEV) infection results in hepatitis E, an acute and self-limited disease. The virus is transmitted in a faecal–oral manner and is a major cause of viral hepatitis in much of the developing world, where it causes rampant sporadic infections and large epidemics. A curious feature of hepatitis E is the unusually high rates of mortality that are observed in pregnant women, in whom the disease is exacerbated by the development of fulminant liver disease. In the absence of viable in vitro propagation systems, several geographical isolates of HEV have been maintained in vivo in nonhuman primates and, subsequently, the viral genome has been cloned and sequenced. HEV has been classified provisionally into a separate family known as the HEV-like viruses, which has at least four recognised genotypes, but has only a single serotype. The viral genome is a positive-stranded (+)RNA of ~7.5 kb and encodes at least three proteins. Open reading frame 1 (ORF1) encodes the viral nonstructural polyprotein, which has domains that are homologous to some of the replication and processing enzymes found in other +RNA viruses. The HEV protein itself remains poorly characterised. The protein encoded by open reading frame 2 (ORF2) is the major HEV capsid protein, and the protein encoded by open reading frame 3 (ORF3) appears to be involved in virus–host interactions. Several questions related to the biology, epidemiology and pathogenesis of HEV remain unanswered; the progress of a few of these is reviewed here.

scholarly journals Analysis of in vitro and in vivo products of the TMV 30kDa open reading frame using antisera raised against a synthetic peptide

FEBS Letters ◽  
1983 ◽  
Vol 164 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Paula A. Kiberstis ◽  
Antonello Pessi ◽  
Eric Atherton ◽  
Richard Jackson ◽  
Tony Hunter ◽  
...  
Keyword(s):  
Synthetic Peptide ◽  
Open Reading Frame ◽  
Reading Frame

scholarly journals Complete Genome Sequence of a Novel Human Betapapillomavirus Isolated from a Skin Sample

2017 ◽  
Vol 5 (13) ◽  
Author(s):  
Sankhadeep Dutta ◽  
Alexis Robitaille ◽  
Dana E. Rollison ◽  
Massimo Tommasino ◽  
Tarik Gheit
Keyword(s):  
Human Papillomavirus ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Genetic Characterization ◽  
Open Reading Frame ◽  
Skin Sample ◽  
Reading Frame ◽  
Beta 2

ABSTRACT We report the genetic characterization of a new papillomavirus (HPV_MTS1) isolated and fully cloned from a skin swab. The L1 open reading frame of HPV_MTS1 was 85% identical to its closest human papillomavirus (HPV) type 80, which belongs to the species beta-2 of the genus Betapapillomavirus, hence qualifying it as a new HPV type.

scholarly journals Murine Cytomegalovirus Open Reading Frame M27 Plays an Important Role in Growth and Virulence in Mice

2001 ◽  
Vol 75 (4) ◽  
pp. 1697-1707 ◽  
Author(s):  
Gerardo Abenes ◽  
Manfred Lee ◽  
Erik Haghjoo ◽  
Tuong Tong ◽  
Xiaoyan Zhan ◽  
...  
Keyword(s):  
Scid Mice ◽  
Open Reading Frame ◽  
Murine Cytomegalovirus ◽  
Wild Type Virus ◽  
Wild Type ◽  
Reading Frame ◽  
Viral Virulence ◽  
Carboxyl Terminal

ABSTRACT Using a Tn3-based transposon mutagenesis approach, we have generated a pool of murine cytomegalovirus (MCMV) mutants. In this study, one of the mutants, RvM27, which contained the transposon sequence at open reading frame M27, was characterized both in tissue culture and in immunocompetent BALB/c mice and immunodeficient SCID mice. Our results suggest that the M27 carboxyl-terminal sequence is dispensable for viral replication in vitro. Compared to the wild-type strain and a rescued virus that restored the M27 region, RvM27 was attenuated in growth in both BALB/c and SCID mice that were intraperitoneally infected with the viruses. Specifically, the titers of RvM27 in the salivary glands, lungs, spleens, livers, and kidneys of the infected SCID mice at 21 days postinfection were 50- to 500-fold lower than those of the wild-type virus and the rescued virus. Moreover, the virulence of the mutant virus appeared to be attenuated, because no deaths occurred among SCID mice infected with RvM27 for up to 37 days postinfection, while all the animals infected with the wild-type and rescued viruses died within 27 days postinfection. Our observations provide the first direct evidence to suggest that a disruption of M27 expression results in reduced viral growth and attenuated viral virulence in vivo in infected animals. Moreover, these results suggest that M27 is a viral determinant required for optimal MCMV growth and virulence in vivo and provide insight into the functions of the M27 homologues found in other animal and human CMVs as well as in other betaherpesviruses.

Cloning and characterization of theddsAgene encoding decaprenyl diphosphate synthase fromRhodobacter capsulatusB10

2006 ◽  
Vol 52 (12) ◽  
pp. 1141-1147 ◽  
Author(s):  
Xinyi Liu ◽  
Haizhen Wu ◽  
Jiang Ye ◽  
Qinsheng Yuan ◽  
Huizhan Zhang
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Rhodobacter Capsulatus ◽  
Open Reading Frame ◽  
High Similarity ◽  
Reading Frame ◽  
Endogenous Production ◽  
Genome Library

A decaprenyl diphosphate synthase gene (ddsA, GenBank accession No. DQ191802) was cloned from Rhodobacter capsulatus B10 by constructing and screening the genome library. An open reading frame of 1002 bp was revealed from sequence analysis. The deduced polypeptide consisted of 333 amino acids residues with an molecular mass of about 37 kDa. The DdsA protein contained the conserved amino acid sequence (DDXXD) of E-type polyprenyl diphosphate synthase and showed high similarity to others. In contrast, DdsA showed only 39% identity to a solanesyl diphosphate synthase cloned from R. capsulatus SB1003. DdsA was expressed successfully in Escherichia coli. Assaying the enzyme in vivo found it made E.coli synthesize UQ-10 in addition to the endogenous production UQ-8.Key words: ubiquinone, polyprenyl diphosphate synthase, gene expression, Rhodobacter capsulatus.

scholarly journals Murine Cytomegalovirus Containing a Mutation at Open Reading Frame M37 Is Severely Attenuated in Growth and Virulence In Vivo

2000 ◽  
Vol 74 (23) ◽  
pp. 11099-11107 ◽  
Author(s):  
Manfred Lee ◽  
Jianqiao Xiao ◽  
Erik Haghjoo ◽  
Xiaoyan Zhan ◽  
Gerry Abenes ◽  
...  
Keyword(s):  
Scid Mice ◽  
Open Reading Frame ◽  
Murine Cytomegalovirus ◽  
Wild Type ◽  
Reading Frame ◽  
Viral Mutant ◽  
Intraperitoneal Infection ◽  
Nih 3T3

ABSTRACT A pool of murine cytomegalovirus (MCMV) mutants was generated by using a Tn3-based transposon mutagenesis procedure. One of the mutants, RvM37, which contained the transposon sequence at open reading frame M37, was characterized both in tissue culture and in immunocompetent BALB/c and immunodeficient SCID mice. Our results provide the first direct evidence to suggest that M37 is not essential for viral replication in vitro in NIH 3T3 cells. Compared to the wild-type strain and a rescued virus that restored the M37 region, the viral mutant was severely attenuated in growth in both BALB/c and SCID mice after intraperitoneal infection. Specifically, titers of the Smith strain and rescued virus in the salivary glands, lungs, spleens, livers, and kidneys of the SCID mice at 21 days postinfection were about 5 × 105, 2 × 105, 5 × 104, 5 × 103, and 1 × 104 PFU/ml of organ homogenate, respectively; in contrast, titers of RvM37 in these organs were less than 102 PFU/ml of organ homogenate. Moreover, the virulence of the mutant virus appeared to be significantly attenuated because none of the SCID mice infected with RvM37 had died by 120 days postinfection, while all animals infected with the wild-type and rescued viruses had died by 26 days postinfection. Our results suggest that M37 probably encodes a virulence factor and is required for MCMV virulence in SCID mice and for optimal viral growth in vivo.

scholarly journals Isolation and Characterization of IS1409, an Insertion Element of 4-Chlorobenzoate-DegradingArthrobacter sp. Strain TM1, and Development of a System for Transposon Mutagenesis

2001 ◽  
Vol 183 (12) ◽  
pp. 3729-3736 ◽  
Author(s):  
Karl-Heinz Gartemann ◽  
Rudolf Eichenlaub
Keyword(s):  
Resistance Genes ◽  
Micrococcus Luteus ◽  
Transposon Mutagenesis ◽  
Open Reading Frame ◽  
Insertion Element ◽  
Reading Frame ◽  
Isolation And Characterization ◽  
Insertion Elements

ABSTRACT A new insertion element of 1,449 bp with 25-bp perfect terminal repeats, designated IS1409, was identified in the chromosome of 4-chlorobenzoate-degrading Arthrobactersp. strain TM1 NCIB12013. Upon insertion, IS1409 causes a target duplication of 8 bp. IS1409 carries only a single open reading frame of 435 codons encoding the transposase TnpA. Both TnpA and the overall organization of IS1409are highly similar to those of some related insertion elements of the ISL3 group (J. Mahillon and M. Chandler, Microbiol. Mol. Biol. Rev. 62:725–774, 1998). IS1409 was also found in other 4-chlorobenzoate-degrading Arthrobacter strains and Micrococcus luteus. Based on IS1409, a series of transposons carrying resistance genes for chloramphenicol and gentamicin were constructed. These transposons were used to demonstrate transposition events in vivo and to mutagenizeArthrobacter sp. strains.

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