scholarly journals Partial Characterization of a Closterovirus Associated with Apple Mealybug-Transmitted Little Cherry Disease in North America

2001 ◽  
Vol 91 (3) ◽  
pp. 268-273 ◽  
Author(s):  
K. C. Eastwell ◽  
M. G. Bernardy
Keyword(s):  
North America ◽  
Rna Polymerase ◽  
Sweet Cherry ◽  
Distinct Species ◽  
Economic Problem ◽  
Western North America ◽  
Rna Dependent Rna Polymerase ◽  
Virus Particles ◽  
Similar Disease

Little cherry disease (LChD) is a serious economic problem of sweet cherry production in western North America where apple mealybug is the principle vector. LChD is associated with a distinct species of double-stranded (ds) RNA. In this study, filamentous virus particles were purified from LChD-infected trees and shown to contain single-stranded RNA corresponding to the previously reported dsRNA isolated from infected trees. The virus particles were characterized and were similar to monopartite members of the genus Closterovirus. A portion of the genome was sequenced and found to be most closely related to the RNA-dependent RNA polymerase of Grapevine leafroll-associated virus-3, a mealybug-transmitted closterovirus. The characteristics of the mealybug-transmitted Little cherry virus in North America are very different from those of a closterovirus associated with a similar disease in Europe.

scholarly journals Analysis of Ribonucleotide 5′-Triphosphate Analogs as Potential Inhibitors of Zika Virus RNA-Dependent RNA Polymerase by Using Nonradioactive Polymerase Assays

2016 ◽  
Vol 61 (3) ◽  
Author(s):  
Gaofei Lu ◽  
Gregory R. Bluemling ◽  
Paul Collop ◽  
Michael Hager ◽  
Damien Kuiper ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Zika Virus ◽  
Nonstructural Protein ◽  
Rna Dependent Rna Polymerase ◽  
Antiviral Compounds ◽  
Double Stranded Dna ◽  
Virus Rna ◽  
Potential Inhibitors

ABSTRACT Zika virus (ZIKV) is an emerging human pathogen that is spreading rapidly through the Americas and has been linked to the development of microcephaly and to a dramatically increased number of Guillain-Barré syndrome cases. Currently, no vaccine or therapeutic options for the prevention or treatment of ZIKV infections exist. In the study described in this report, we expressed, purified, and characterized full-length nonstructural protein 5 (NS5) and the NS5 polymerase domain (NS5pol) of ZIKV RNA-dependent RNA polymerase. Using purified NS5, we developed an in vitro nonradioactive primer extension assay employing a fluorescently labeled primer-template pair. Both purified NS5 and NS5pol can carry out in vitro RNA-dependent RNA synthesis in this assay. Our results show that Mn2+ is required for enzymatic activity, while Mg2+ is not. We found that ZIKV NS5 can utilize single-stranded DNA but not double-stranded DNA as a template or a primer to synthesize RNA. The assay was used to compare the efficiency of incorporation of analog 5′-triphosphates by the ZIKV polymerase and to calculate their discrimination versus that of natural ribonucleotide triphosphates (rNTPs). The 50% inhibitory concentrations for analog rNTPs were determined in an alternative nonradioactive coupled-enzyme assay. We determined that, in general, 2′-C-methyl- and 2′-C-ethynyl-substituted analog 5′-triphosphates were efficiently incorporated by the ZIKV polymerase and were also efficient chain terminators. Derivatives of these molecules may serve as potential antiviral compounds to be developed to combat ZIKV infection. This report provides the first characterization of ZIKV polymerase and demonstrates the utility of in vitro polymerase assays in the identification of potential ZIKV inhibitors.

Biochemical Characterization of Respiratory Syncytial Virus RNA-Dependent RNA Polymerase Complex

2020 ◽  
Vol 6 (10) ◽  
pp. 2800-2811
Author(s):  
Anand Balakrishnan ◽  
Edmund Price ◽  
Catherine Luu ◽  
Jacob Shaul ◽  
Charles Wartchow ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Rna Polymerase ◽  
Biochemical Characterization ◽  
Rna Dependent Rna Polymerase ◽  
Polymerase Complex ◽  
Virus Rna ◽  
Syncytial Virus

Late Cambrian ptychaspidid trilobites from western Utah: implications for trilobite systematics and biostratigraphy

2005 ◽  
Vol 142 (4) ◽  
pp. 377-398 ◽  
Author(s):  
J. M. ADRAIN ◽  
S. R. WESTROP
Keyword(s):  
North America ◽  
Distinct Species ◽  
Western North America ◽  
Closely Related Species ◽  
Widespread Species ◽  
Late Cambrian ◽  
South Central ◽  
New Information ◽  
The Family ◽  
Notch Peak

The Notch Peak Formation (Late Cambrian, Sunwaptan) of western Utah yields diverse silicified trilobite faunas that provide new information on the anatomy of many taxa. The family Ptychaspididae Raymond, 1924, is represented by species of Keithiella Rasetti, 1944; Idiomesus Raymond, 1924; Euptychaspis Ulrich in Bridge, 1931; and Macronoda Lochman, 1964. At least four species are new, of which E. lawsonensis and M. notchpeakensis are named formally. Much previous work on Late Cambrian trilobites has emphasized biostratigraphic utility and the recognition of geographically widespread species. Data from new silicified collections indicate that this approach is difficult to justify because many putative ‘index species’ actually represent a plexus of closely related species whose biostratigraphic significance has yet to be determined. One such plexus is represented by E. kirki Kobayashi, 1935, whose previously reported occurrences in Texas, Oklahoma, Utah, Nevada and northern Canada record at least four distinct species. Similarly, Macronoda can now be shown to consist of at least five late Sunwaptan species in south-central and western North America.

Production and characterization of active hepatitis C virus RNA-dependent RNA polymerase

2010 ◽  
Vol 71 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Kisun Ryu ◽  
Kyun-Hwan Kim ◽  
Seong-Yeon Yoo ◽  
Eun-Young Lee ◽  
Keo-Heun Lim ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Rna Polymerase ◽  
Hepatitis C Virus Rna ◽  
Rna Dependent Rna Polymerase ◽  
Virus Rna
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