Both nonstructural proteins NS2B and NS3 are required for the proteolytic processing of dengue virus nonstructural proteins
| Autor: | M. Pethel, B. Falgout, Ching-Juh Lai, Yi-Ming Zhang |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Polyproteins
viruses medicine.medical_treatment Molecular Sequence Data Immunology Gene Expression Vaccinia virus Viral Nonstructural Proteins Biology Dengue virus Cleavage (embryo) medicine.disease_cause Microbiology law.invention Viral Proteins law Sequence Homology Nucleic Acid Virology Endopeptidases medicine Amino Acid Sequence Peptide sequence chemistry.chemical_classification NS3 Protease Base Sequence Serine Endopeptidases virus diseases Dengue Virus biochemical phenomena metabolism and nutrition Molecular biology digestive system diseases Amino acid chemistry Biochemistry Insect Science DNA Viral Trans-Activators Recombinant DNA Protein Processing Post-Translational Sequence Alignment RNA Helicases Research Article |
| Zdroj: | Journal of Virology. 65:2467-2475 |
| ISSN: | 1098-5514 0022-538X |
| DOI: | 10.1128/jvi.65.5.2467-2475.1991 |
| Popis: | The cleavages at the junctions of the flavivirus nonstructural (NS) proteins NS2A/NS2B, NS2B/NS3, NS3/NS4A, and NS4B/NS5 share an amino acid sequence motif and are presumably catalyzed by a virus-encoded protease. We constructed recombinant vaccinia viruses expressing various portions of the NS region of the dengue virus type 4 polyprotein. By analyzing immune precipitates of 35S-labeled lysates of recombinant virus-infected cells, we could monitor the NS2A/NS2B, NS2B/NS3, and NS3/NS4A cleavages. A polyprotein composed of NS2A, NS2B, and the N-terminal 184 amino acids of NS3 was cleaved at the NS2A/NS2B and NS2B/NS3 junctions, whereas a similar polyprotein containing only the first 77 amino acids of NS3 was not cleaved. This finding is consistent with the proposal that the N-terminal 180 amino acids of NS3 constitute a protease domain. Polyproteins containing NS2A and NS3 with large in-frame deletions of NS2B were not cleaved at the NS2A/NS2B or NS2B/NS3 junctions. Coinfection with a recombinant expressing NS2B complemented these NS2B deletions for NS2B/NS3 cleavage and probably also for NS2A/NS2B cleavage. Thus, NS2B is also required for the NS2A/NS2B and NS2B/NS3 cleavages and can act in trans. Other experiments showed that NS2B was needed, apparently in cis, for NS3/NS4A cleavage and for a series of internal cleavages in NS3. Indirect evidence that NS3 can also act in trans was obtained. Models are discussed for a two-component protease activity requiring both NS2B and NS3. |
| Databáze: | OpenAIRE |
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