Differential Proteolytic Activities of Precursor and Mature Forms of the 24K Proteinase of Grapevine Fanleaf Nepovirus
| Autor: | Monique Pinck, Nicolas Bardonnet, L. Pinck, Martine Viry, Rogerio Margis |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Polyproteins
Base Sequence Viral Core Proteins Molecular Sequence Data Nepovirus RNA Grapevine fanleaf virus DNA-Directed RNA Polymerases Biology Cleavage (embryo) biology.organism_classification Cysteine Endopeptidases chemistry.chemical_compound medicine.anatomical_structure chemistry Reticulocyte Biochemistry Proteinase 3 Virology RNA polymerase medicine Protein Precursors Protein Processing Post-Translational |
| Zdroj: | Virology. 200:79-86 |
| ISSN: | 0042-6822 |
| DOI: | 10.1006/viro.1994.1165 |
| Popis: | The presence of a genome-linked protein (VPg) at the RNA 5′-end of the genome is a characteristic of different groups of animal and plant positive-sense single-stranded RNA viruses. These viruses express their structural and functional proteins from polyproteins that are sequentially processed by at least one viral proteinase. The grapevine fanleaf nepovirus 24K chymotrypsin-like cysteine proteinase, located between the VPg and the RNA polymerase in the RNA-1 encoded polyprotein P1, is active in its free form and in various precursors forms. The VPg proteinase precursor (VPg-Pro) constitutes a stable protein and its maturation in the reticulocyte lysate system occurs at a very low rate. Differences on cleavage activity were observed between the proteinase and its VPg-Pro precursor forms, depending upon the cleavage site considered. The proteinase alone has a greater cleavage efficiency than VPg-Pro at the Arg 605 /Gly 606 and Cys 257 /Ala 258 sites of polyprotein P2. On the other hand, the presumed Cys 415 /Ala 416 site, present at the amino terminus of polyprotein P1, was preferentially cleaved by the VPg-Pro precursor. During their in vitro maturation, proteins containing the VPg proteinase-polymerase coding region or the proteinase-polymerase region were similar in their ability to cleave in cis between the proteinase and the RNA polymerase. |
| Databáze: | OpenAIRE |
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