• The Plant Pathology Journal
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• v.29 no.4
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• pp.454-459
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• 2013

The Potexvirus Alternanthera mosaic virus (AltMV) has multifunctional triple gene block (TGB) proteins, among which our studies have focused on the properties of the TGB1 protein. The TGB1 of AltMV has functions including RNA binding, RNA silencing suppression, and cell-to-cell movement, and is known to form homologous interactions. The helicase domains of AltMV TGB1 were separately mutated to identify which regions are involved in homologous TGB1 interactions. The yeast two hybrid system and Bimolecular Fluorescence Complementation (BiFC) in planta were utilized to examine homologous interactions of the mutants. Helicase motif I of AltMV TGB1 was found to be critical to maintain homologous interactions. Mutations in the remaining helicase motifs did not inhibit TGB1 homologous interactions. In the absence of homologous interaction of TGB1, subcellular localization of helicase domain I mutants showed distinctively different patterns from that of WT TGB1. These results provide important information to study viral movement and replication of AltMV.

• Journal of the Korean Magnetic Resonance Society
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• v.20 no.1
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• pp.22-26
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• 2016

FANCJ is a DNA helicase which contributes genome stability by resolving G-quadruplex DNA from 5' to 3' direction. In addition to main ATPase helicase core, FANCJ has the protein binding region at its C-terminal part. BRCA1 and BLM are the binding partner of FANCJ and these protein-protein interactions contribute genomic stability and the proper response to replication stress. As the first attempt for studying FANCJ-BLM interaction, we prepared BLM binding region of FANCJ and characterized with CD and NMR spectroscopy. FANCJ (881-941) with N-ter 6xHis was purified as the oligomer. Secondary structure prediction based on CD data revealed that FANCJ (881-941) composed with ${\beta}$ sheet, turn and coils.$^1H-^{15}N$ HSQC spectra showed nonhomogeneous peak intensities with less number of peaks comparing than the number of amino acids in the construct. It indicated that optimization should be necessary for detailed further structural studies.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.2070-2073
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• 2017

We have discovered a novel chemical compound, (E)-3-(furan-2-yl)-N-(4-sulfamoylphenyl) acrylamide, that suppresses the enzymatic activities of SARS coronavirus helicase. To determine the inhibitory effect, ATP hydrolysis and double-stranded DNA unwinding assays were performed in the presence of various concentrations of the compound. Through these assays, we obtained $IC_{50}$ values of $2.09{\pm}0.30{\mu}M$ (ATP hydrolysis) and $13.2{\pm}0.9{\mu}M$ (DNA unwinding), respectively. Moreover, we found that the compound did not have any significant cytotoxicity when $40{\mu}M$ of it was used. Our results showed that the compound might be useful to be developed as an inhibitor against SARS coronavirus.

• BMB Reports
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• v.40 no.1
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• pp.7-14
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• 2007

Helicases are ubiquitous enzymes, which utilize the energy liberated during nucleotide triphosphate hydrolysis to separate double-stranded nucleic acids into single strands. These enzymes are very attractive targets for the development of new antibacterial compounds. The PcrA DNA helicase from Staphylococcus aureus is a good candidate for drug discovery. This enzyme is unique in the genome of S. aureus and essential for this bacterium. Furthermore, it has recently been published that it is possible to identify inhibitors of DNA helicases such as PcrA. In this report, we study the properties of recombinant PcrA from S. aureus purified from Escherichia coli to develop ATPase and helicase assays to screen for inhibitors.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.260-264
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• 2006

Talaromyces flavus mediates the transmission of Apple stem grooving virus (ASGV) to several host plants. The ASGV-F carried by T.flavus was partially purified from the fungus. Based on sequence analysis and homology searches, this is closely related to other ASGV strains isolated from host plants. The partially purified viral coat protein (CP) was separated on a 12% SDS-polyacrylamide gel and analyzed by Western blotting with an ASGV anti-serum. A single band at 28 kDa reacted with the ASGV anti-serum. The deduced amino acid sequence of the ORF-l showed conserved domains, including an NTP-binding helicase motif, GFAGSGKT. The amino acid sequences of the helicase and CP showed strong homology to other ASGV strains (98%). All ASGV isolated from plants and fungi had salt bridges composed of the CP and the GFAGSGKT motif of the helicase, which are commonly conserved in plant viruses. These results suggest that ASGV-F is one of ASGV strains isolated from T.flavus based on sequence similarity as well as the serological analysis of CP.

• The Journal of Korean Society of Virology
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• v.27 no.1
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• pp.29-37
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• 1997

To use recombinant viruses with wider host range as viral insecticides, we investigated the characteristics and pathogenicity of host range expanded recombinant viruses in insect cells. We compared host range expanded recombinant viruses, RecS-B6 and RecB-8, constructed by cotransfection of Autographa californica nuclear polyhedrosis virus (AcNPV) and Bombyx mori NPV (BmNPV), to host range expanded AcNPV, Ac-BH, by substitution of the 0.6 Kb fragment of the BmNPV helicase gene. Restriction endonuclease profiles of RecS-B6 and RecB-8 DNAs were different from those of parent viruses. Nucleotide sequence analysis of the 0.6 Kb region in the putative helicase gene of RecS-B6 and RecB-8 showed that their structures were identical to the counterpart region of BmNPV. Comparison of viral replication of these recombinant viruses in Sf-21 and BmN-4 cells showed that Ac-BH, compared to wild type viruses, replicated well in BmN-4 cells but poorly in Sf-21 cells. In contrast, RecS-B6 and RecB-8 replicated relatively well in both cells compared to parent viruses. These results may imply that random genomic recombinant viruses, RecS-B6 and RecB-8, possess better potential as viral pesticides than helicase-mediated recombinant virus, Ac-BH.

• The Journal of the Korean bone and joint tumor society
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• v.8 no.3
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• pp.69-75
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• 2002

Werner's syndrome is a rare autosomal recessive disorder manifesting as premature aging. It is also known to be characterized by a high frequency of malignant tumors, especially sarcomas. However, Werner's syndrome may be not only a premature aging disease but also a cancer syndrome, because the malignant tumors in these patients are different from those of normal population with respect to involved site, histological type, and age of onset. Recent studies found Werner's syndrome was caused by a mutation of Werner helicase suggesting that WRN helicase may participate in metabolism and repair of DNA. And a dysfunction of WRN helicase may induce the genomic instability causing somatic mutations. Further studies of Werner's syndrome associated with sarcoma might give much informations about the normal aging process and the pathogenesis of sarcomas.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.289-294
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• 2011

We investigated the cold shock sensitivity of DEAD-box RNA helicase gene deleted strains of in Bacillus subtilis CU1065. To understand cold shock effects, cells were cultivated at $37^{\circ}C$ to log phase ($O.D_{600}$=0.5-0.6) and then temperature was shifted to $15^{\circ}C$. Cold shock slow down the growth rate of wild type and deleted strains of DEAD-box RNA helicase gene (ydbR, yfmL, yqfR, deaD). The growth rate of ydbR deleted strain is 5 times severely reduced compared to that of wild type strain (CU1065). But the growth rate of other three (yfmL, yqfR, deaD) deleted strains is nearly equal to the growth rate of wild type. Compared to $37^{\circ}C$, the amount of ydbR and yqfR mRNA transcripts are increased at the growth temperature of $15^{\circ}C$. On the other hands the mRNA transcripts of yfmL and deaD are not changed at both conditions of $37^{\circ}C$ and $15^{\circ}C$. Upon cold shock treatment ydbR mRNA transcript is clearly increased. After treatment of rifampicin (bacteria transcription inhibitor) the amount of ydbR mRNA was measured. Temperature shift from $37^{\circ}C$ to $15^{\circ}C$ and rifampicin treatment showed slowly decay of ydbR mRNA. But at $37^{\circ}C$ and rifampicin treatment ydbR mRNA is rapidly reduced. These results showed that cold shock induction of ydbR mRNA resulted from the stability of ydbR mRNA and not from the transcription induction of ydbR. In relation to these results, we found the cold box element of csp (cold shock protein gene) in 5' untranslated region of ydbR gene. Cold shock induction of ydbR is caused by the stability of ydbR mRNA like the stability of csp mRNA.

• Korean Journal of Veterinary Research
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• v.58 no.1
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• pp.45-49
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• 2018

The helicase genes and hypervariable regions (HVRs) of three avian hepatitis E viruses (HEVs) detected at three different farms were sequenced and characterized. Two isolates (DW-L and GI-B2) were classified as genotype 2 and one isolate (GR-B) was classified as genotype 1. A phylogenetic tree, based on the helicase gene and HVR nucleotide sequences, revealed the newly detected viruses and other avian HEVs were classified similarly. Unlike previously reported avian HEVs, the DW-L isolate detected in broiler breeders with characteristic lesions of avian HEV had no proline-rich motif in its HVR, suggesting that the proline-rich motif is non-essential for viral replication and infection.

• Journal of Sericultural and Entomological Science
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• v.38 no.1
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• pp.42-47
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• 1996

To investigate the host range determining factors of nuclear polyhedrois virus (NPV), Autographa california NPV and Bombyx mori NPV were coinfected into the two different cell lines, BmN-4 and Sf-9. The recombinant baculoviruses, RecS-A6 and RecB-727 which have an expanded host range, were isolated from Sf-9 and BmN-4 cell lines, respectively. The molecular biological characteristics of the recombinant baculoviruses were investigated. The pathogenicity of RecB-727 was similar to that of wild type BmNPV, while the pathogenicity of RecS-A6 was relatively lower than that of wild type BmNPV. The restriction enzyme digestion patterns of parental viruses and recombinant viruses showed that the recombinant virus has an expanded host range by genetic recombination. Southern blot analysis revealed that the p10 gene of RecB-727 was derived from AcNPV genomic DNA, while RecS-A6 has p10 gene of BmNPV in a viral genome. To investigate the host range expansion mechanism of recombinant baculovirus, HindIII-SacI 0.6 kb DNA fragments of RecS-A6 and RecB-727 were cloned and sequenced. The results showed that of wild type BmNPV helicase gene, suggesting that the expanded host range of recombinant baculoviruses was due to the insertion of BmNPV helicase gene into AcNPV viral genome.