The Putative Replicase of the Cocksfoot Mottle Sobemovirus Is Translated as a Part of the Polyprotein by -1 Ribosomal Frameshift
| Autor: | Mart Saarma, Erkki Truve, Tiina Tamm, Kristiina Mäkinen, Vigfrid Næss, Anu Aaspöllu |
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| Jazyk: | angličtina |
| Předmět: |
Cocksfoot mottle virus
Molecular Sequence Data RNA-dependent RNA polymerase Biology Sobemovirus Ribosomal frameshift Frameshift mutation Open Reading Frames 03 medical and health sciences Mosaic Viruses Virology Luteovirus Amino Acid Sequence 030304 developmental biology Genetics 0303 health sciences Translational frameshift Base Sequence Sequence Homology Amino Acid 030302 biochemistry & molecular biology Nucleic acid sequence RNA-Dependent RNA Polymerase biology.organism_classification Open reading frame Protein Biosynthesis Nucleic Acid Conformation RNA Viral Ribosomes |
| Zdroj: | Virology. (2):566-571 |
| ISSN: | 0042-6822 |
| DOI: | 10.1006/viro.1995.1118 |
| Popis: | The polyprotein of cocksfoot mottle sobemovirus (CfMV) is encoded by two overlapping open reading frames (ORF). The ORF 2a codes for the putative VPg and serine protease and the ORF 2b codes for the putative replicate. The consensus signals for a -1 ribosomal frameshifting event are found at the very beginning of the overlapping region of these ORFs. The shifty heptanucleotide in CfMV is UUUAAAC, and the secondary structure after the shifty sequence is predicted to be a stem-loop. In vitro translation of the CfMV RNA in wheat germ extract produced proteins of several sizes, including one of 100 kDa. According to the nucleotide sequence data, no single ORF is capable of directing the synthesis of a 100-kDa protein. A chimetic β-glucuronidase-CfMV cDNA containing the entire ORF 2a and 2b overlap region including frameshift signals was constructed. A trans-frame protein of 108 kDa was produced from this construct with an efficiency of 26-29% by in vitro translation in wheat germ extract. CfMV is the first sobemovirus in which the putative replicase is reported to be produced as a part of a polyprotein by a -1 frameshift event. The replicases of the sobemoviruses are related to the luteovirus subgroup II replicases, which are known to be produced by -1 ribosomal frameshift. The reported amino acid sequences of the putative replicases of sobemo- and subgroup II luteoviruses were compared to that of the putative replicase of CfMV. This comparison revealed more extensive homology between these groups than previously reported. |
| Databáze: | OpenAIRE |
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