Evidence that the N-terminal domain of nonstructural protein NS3 from yellow fever virus is a serine protease responsible for site-specific cleavages in the viral polyprotein
| Autor: | Robert J. Fletterick, J F Bazan, David W. McCourt, T J Chambers, R C Weir, Charles M. Rice, Arash Grakoui |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Genes
Viral viruses medicine.medical_treatment DNA Mutational Analysis Viral Nonstructural Proteins Virus Viral Proteins Flaviviridae Capsid medicine Cloning Molecular Protein Precursors Viral Structural Proteins Serine protease NS3 Multidisciplinary Protease biology Viral Core Proteins Serine Endopeptidases biology.organism_classification Virology Molecular biology NS2-3 protease Flavivirus Protein Biosynthesis biology.protein Yellow fever virus MASP1 Research Article |
| Zdroj: | Proceedings of the National Academy of Sciences. 87:8898-8902 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.87.22.8898 |
| Popis: | Sequence homology and molecular modeling studies have suggested that the N-terminal one-third of the flavirvirus nonstructural protein NS3 functions as a trypsin-like serine protease. To examine the putative proteolytic activity of NS3, segments of the yellow fever virus genome were subcloned into plasmid transcription/translation vectors and cell-free translation products were characterized. The results suggest that a protease activity encoded within NS2B and the N-terminal one-third of yellow fever virus NS3 is capable of cis-acting site-specific proteolysis at the NS2B-NS3 cleavage site and dilution-insensitive cleavage of the NS2A-NS2B site. Site-directed mutagenesis of the His-53, Asp-77, and Ser-138 residues of NS3 that compose the proposed catalytic triad implicates this domain as a serine protease. Infectious virus was not recovered from mammalian cells transfected with RNAs transcribed from full-length yellow fever virus cDNA templates containing mutations at Ser-138 (which abolish or dramatically reduce protease activity in vitro), suggesting that the protease is required for viral replication. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|