scholarly journals Roles of the genomic sequence surrounding the stem-loop structure in the junction region including the 3′ terminus of open reading frame 1 in hepatitis E virus replication

2018 ◽  
Vol 90 (9) ◽  
pp. 1524-1531 ◽  
Author(s):  
Dianjun Cao ◽  
Yan-Yan Ni ◽  
Michelle Walker ◽  
Yao-Wei Huang ◽  
Xiang-Jin Meng
Keyword(s):  
Hepatitis E Virus ◽  
Genomic Sequence ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Loop Structure ◽  
Junction Region ◽  
Stem Loop ◽  
Reading Frame ◽  
Stem Loop Structure ◽  
Open Reading Frame 1

scholarly journals RNA 5′-Triphosphatase Activity of the Hepatitis E Virus Helicase Domain

2010 ◽  
Vol 84 (18) ◽  
pp. 9637-9641 ◽  
Author(s):  
Yogesh A. Karpe ◽  
Kavita S. Lole
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Helicase Domain ◽  
Reading Frame ◽  
Essential Step ◽  
Positive Sense ◽  
Rna Triphosphatase ◽  
Rna Duplexes ◽  
Open Reading Frame 1

ABSTRACT Hepatitis E virus (HEV) has a positive-sense RNA genome with a 5′-m7G cap. HEV open reading frame 1 (ORF1) encodes a polyprotein with multiple enzyme domains required for replication. HEV helicase is a nucleoside triphosphatase (NTPase) with the ability to unwind RNA duplexes in the 5′-to-3′ direction. When incubated with 5′-[γ-32P]RNA and 5′-[α-32P]RNA, HEV helicase released 32P only from 5′-[γ-32P]RNA, showing specificity for the γ-β-triphosphate bond. Removal of γ-phosphate from the 5′ end of the primary transcripts (pppRNA to ppRNA) by RNA triphosphatase is an essential step during cap formation. It is suggested that HEV employs the helicase to mediate the first step of 5′ cap synthesis.

Cloning, sequencing, and expression of the hepatitis E virus (HEV) nonstructural open reading frame 1 (ORF1)

2000 ◽  
Vol 60 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Israrul Haque Ansari ◽  
Santosh Kumar Nanda ◽  
Hemlata Durgapal ◽  
Shipra Agrawal ◽  
Sujit Kumar Mohanty ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Sequencing And Expression ◽  
Open Reading Frame 1

scholarly journals Initiation at the Third In-Frame AUG Codon of Open Reading Frame 3 of the Hepatitis E Virus Is Essential for Viral Infectivity In Vivo

2007 ◽  
Vol 81 (6) ◽  
pp. 3018-3026 ◽  
Author(s):  
Y. W. Huang ◽  
T. Opriessnig ◽  
P. G. Halbur ◽  
X. J. Meng
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Initiation Site ◽  
Open Reading Frame ◽  
Virus Infectivity ◽  
Single Mutation ◽  
Junction Region ◽  
Reading Frame ◽  
The Third

ABSTRACT To determine the initiation strategy of the hepatitis E virus (HEV) open reading frame 3 (ORF3), we constructed five HEV mutants with desired mutations in the ORF1 and ORF2 junction region and tested their levels of in vivo infectivity in pigs. A mutant with a C-terminally truncated ORF3 is noninfectious in pigs, indicating that an intact ORF3 is required for in vivo infectivity. Mutations with substitutions in the first in-frame AUG in the junction region or with the same T insertion at the corresponding position of HEV genotype 4 did not affect the virus infectivity or rescue, although mutations with combinations of the two affected virus recovery efficiency, and a single mutation at the third in-frame AUG completely abolished virus infectivity in vivo, indicating that the third in-frame AUG in the junction region is required for virus infection and is likely the authentic initiation site for ORF3. A conserved double stem-loop RNA structure, which may be important for HEV replication, was identified in the junction region. This represents the first report of using a unique homologous pig model system to study the molecular mechanism of HEV replication and to systematically and definitively identify the authentic ORF3 initiation site.

scholarly journals A Group IIC-Type Intron Interrupts the rRNA Methylase Gene of Geobacillus stearothermophilus Strain 10

2010 ◽  
Vol 192 (19) ◽  
pp. 5245-5248 ◽  
Author(s):  
Samuel E. Moretz ◽  
Bert C. Lampson
Keyword(s):  
Open Reading Frame ◽  
Loop Structure ◽  
Geobacillus Stearothermophilus ◽  
Stem Loop ◽  
Reading Frame ◽  
Stem Loop Structure ◽  
Insertion Sites ◽  
Methylase Gene

ABSTRACT Group IIC introns insert next to the stem-loop structure of rho-independent transcription terminators, thus avoiding intact genes. The insertion sites of 17 copies of the G.st.I1 intron from Geobacillus stearothermophilus were compared. One copy of the intron was found to interrupt an open reading frame (ORF) encoding an rRNA methylase.

scholarly journals Complete Genome Sequence of Beak and Feather Disease Virus Isolated from an African Grey Parrot in China in 2017

2018 ◽  
Vol 6 (6) ◽  
pp. e01519-17
Author(s):  
Xuejun Guo ◽  
Xinna Ge ◽  
Jianyu Chang
Keyword(s):  
Disease Virus ◽  
Viral Genome ◽  
Loop Structure ◽  
Stem Loop ◽  
Reading Frame ◽  
African Grey Parrot ◽  
Stem Loop Structure ◽  
Grey Parrot ◽  
Feather Disease Virus ◽  
Open Reading Frame 1

ABSTRACT The complete nucleotide (nt) sequence of beak and feather disease virus (BFDV) was determined. The viral genome consists of 1,991 nt, including an 870-nt open reading frame 1 (ORF1), a 744-nt ORF2, a conserved stem-loop structure, and the second hairpin. This is the first reported detection of BFDV in an infected African grey parrot in China.

scholarly journals A CASE OF IMPORT OF GENOTYPE 4 HEPATITIS E VIRUS INTO RUSSIA

2016 ◽  
pp. 64-69 ◽  
Author(s):  
M. I. Mikhailov ◽  
E. Yu. Malinnikova ◽  
K. K. Kyuregyan ◽  
O. V. Isaeva
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Nucleotide Sequences ◽  
Open Reading Frame ◽  
Virus Genotype ◽  
Genotype 4 ◽  
Reading Frame ◽  
Imported Case ◽  
Open Reading Frame 2 ◽  
Open Reading Frame 1

Aim. Description of the first documented case of imported hepatitis E, associated with genotype 4 of HEV and introduced from southern France. Materials and methods. Clinical, epidemiologic and laboratory analysis of the imported case of disease of hepatitis E was carried out. Phylogenetic analysis of nucleotide sequences of HEV isolate, taken from the patient, was carried out. Results. Epidemiologic analysis allowed to assume imported character of the detected case of HEV-infection. Comparative analysis of nucleotide sequences of regions of the open reading frame 2 (300 nt) and open reading frame 1 (721 nt) of HEV genome, isolated from the patient, showed identity of this isolate with variants of genotype 4 HEV, isolated in France in 2009 - 2011 from patients with autochthonous hepatitis E. Conclusion. The results obtained confirm the case of import into Russia of genotype 4 HEV from south-eastern France (Corsica), where spread of this virus genotype is observed in recent years.

scholarly journals Characterization of the 13-KilobaseermF Region of the BacteroidesConjugative Transposon CTnDOT

2001 ◽  
Vol 67 (8) ◽  
pp. 3488-3495 ◽  
Author(s):  
Gabrielle Whittle ◽  
Bonnie D. Hund ◽  
Nadja B. Shoemaker ◽  
Abigail A. Salyers
Keyword(s):  
Common Ancestor ◽  
Open Reading Frame ◽  
Clinical Isolates ◽  
Class I ◽  
Loop Structure ◽  
Conjugative Transposon ◽  
Stem Loop ◽  
Reading Frame ◽  
Stem Loop Structure

ABSTRACT The conjugative transposon CTnDOT is virtually identical over most of its length to another conjugative transposon, CTnERL, except that CTnDOT carries an ermF gene that is not found on CTnERL. In this report, we show that the region containing ermFappears to consist of a 13-kb chimera composed of at least one class I composite transposon and a mobilizable transposon (MTn). Although theermF region contains genes also carried onBacteroides transposons Tn4351 and Tn4551, it does not contain the IS4351element which is found on these transposons. In CTnDOT, insertion of the ermF region occurred near a stem-loop structure at the end of orf2, an open reading frame located immediately downstream of the integrase (int) gene of CTnDOT, and in a region known to be important for excision of CTnERL and CTnDOT. The chimera that comprises the ermF region can apparently no longer excise and circularize, but it contains a functional mobilization region related to that described for theBacteroides MTn Tn4399. Analysis of 19 independent Bacteroides isolates showed that theermF region is located in the same position in all of the strains analyzed and that the compositions of theermF region are almost identical in these strains. Therefore, it appears that CTnDOT-like elements present in community and clinical isolates of Bacteroides were derived from a common ancestor and proliferated in the diverseBacteroides population.

scholarly journals Deletions of the Hypervariable Region (HVR) in Open Reading Frame 1 of Hepatitis E Virus Do Not Abolish Virus Infectivity: Evidence for Attenuation of HVR Deletion Mutants In Vivo

2008 ◽  
Vol 83 (1) ◽  
pp. 384-395 ◽  
Author(s):  
R. S. Pudupakam ◽  
Y. W. Huang ◽  
T. Opriessnig ◽  
P. G. Halbur ◽  
F. W. Pierson ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Hypervariable Region ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Deletion Mutants ◽  
Reading Frame ◽  
Rna Transcripts ◽  
Open Reading Frame 1

ABSTRACT Hepatitis E virus (HEV) is an important human pathogen, although little is known about its biology and replication. Comparative sequence analysis revealed a hypervariable region (HVR) with extensive sequence variations in open reading frame 1 of HEV. To elucidate the role of the HVR in HEV replication, we first constructed two HVR deletion mutants, hHVRd1 and hHVRd2, with in-frame deletion of amino acids (aa) 711 to 777 and 747 to 761 in the HVR of a genotype 1 human HEV replicon. Evidence of HEV replication was detected in Huh7 cells transfected with RNA transcripts from mutant hHVRd2, as evidenced by expression of enhanced green fluorescent protein. To confirm the in vitro results, we constructed three avian HEV mutants with various HVR deletions: mutants aHVRd1, with deletion of aa 557 to 585 (Δ557-585); aHVRd2 (Δ612-641); and aHVRd3 (Δ557-641). Chickens intrahepatically inoculated with capped RNA transcripts from mutants aHVRd1 and aHVRd2 developed active viral infection, as evidenced by seroconversion, viremia, and fecal virus shedding, although mutant aHVRd3, with complete HVR deletion, was apparently attenuated in chickens. To further verify the results, we constructed four additional HVR deletion mutants using the genotype 3 swine HEV as the backbone. Mutants sHVRd2 (Δ722-781), sHVRd3 (Δ735-765), and sHVRd4 (Δ712-765) were shown to tolerate deletions and were infectious in pigs intrahepatically inoculated with capped RNA transcripts from the mutants, whereas mutant sHVRd1 (Δ712-790), with a nearly complete HVR deletion, exhibited an attenuation phenotype in infected pigs. The data from these studies indicate that deletions in HVR do not abolish HEV infectivity in vitro or in vivo, although evidence for attenuation was observed for HEV mutants with a larger or nearly complete HVR deletion.

scholarly journals Antigenic Characterization of ORF2 and ORF3 Proteins of Hepatitis E Virus (HEV)

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1385
Author(s):  
Giulia Pezzoni ◽  
Lidia Stercoli ◽  
Eleonora Pegoiani ◽  
Emiliana Brocchi
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Recombinant Antigen ◽  
Open Reading Frame ◽  
Reading Frame ◽  
E Coli ◽  
Antigenic Characterization ◽  
Antigenic Properties ◽  
Open Reading Frame 2

To evaluate the antigenic properties of Hepatitis E Virus (HEV) Open Reading Frame 2 and 3 (ORF2 and ORF3) codified proteins, we expressed different portions of ORF2 and the entire ORF3 in E. coli, a truncated ORF2, was also expressed in baculovirus. A panel of 37 monoclonal antibodies (MAbs) was raised against ORF2 (1–660 amino acids) and MAbs were mapped and characterized using the ORF2 expressed portions. Selected HEV positive and negative swine sera were used to evaluate ORF2 and ORF3 antigens’ immunogenicity. The MAbs were clustered in six groups identifying six antigenic regions along the ORF2. Only MAbs binding to the sixth ORF2 antigenic region (394–608 aa) were found to compete with HEV positive sera and efficiently catch the recombinant antigen expressed in baculovirus. The ORF2 portion from 394–608 aa demonstrated to include most immunogenic epitopes with 85% of HEV positive swine sera reacting against the region from 461–544 aa. Only 5% of the selected HEV sera reacted against the ORF3 antigen.

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