Nucleoside and RNA triphosphatase activities of orthoreovirus transcriptase cofactor mu2
| Autor: | John S. L. Parker, Jonghwa Kim, Max L. Nibert, Kenneth E. Murray |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Orthoreovirus
Mammalian Biochemistry chemistry.chemical_compound Viral Proteins Adenosine Triphosphate Multienzyme Complexes RNA polymerase RNA triphosphatase Animals Nucleotide Amino Acid Sequence RNA Messenger Molecular Biology Orthoreovirus chemistry.chemical_classification Binding Sites biology Base Sequence Hydrolysis Viral Core Proteins RNA Cell Biology biology.organism_classification Nucleoside-Triphosphatase Reverse transcriptase Recombinant Proteins Acid Anhydride Hydrolases chemistry DNA Viral RNA Viral Triphosphatase Nucleoside |
| Zdroj: | The Journal of biological chemistry. 279(6) |
| ISSN: | 0021-9258 |
| Popis: | The mammalian Orthoreovirus (mORV) core particle is an icosahedral multienzyme complex for viral mRNA synthesis and provides a delimited system for mechanistic studies of that process. Previous genetic results have identified the mORV mu2 protein as a determinant of viral strain differences in the transcriptase and nucleoside triphosphatase activities of cores. New results in this report provided biochemical and genetic evidence that purified mu2 is itself a divalent cation-dependent nucleoside triphosphatase that can remove the 5' gamma-phosphate from RNA as well. Alanine substitutions in a putative nucleotide binding region of mu2 abrogated both functions but did not affect the purification profile of the protein or its known associations with microtubules and mORV microNS protein in vivo. In vitro microtubule binding by purified mu2 was also demonstrated and not affected by the mutations. Purified mu2 was further demonstrated to interact in vitro with the mORV RNA-dependent RNA polymerase, lambda3, and the presence of lambda3 mildly stimulated the triphosphatase activities of mu2. These findings confirm that mu2 is an enzymatic component of the mORV core and may contribute several possible functions to viral mRNA synthesis. |
| Databáze: | OpenAIRE |
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