Characterization of the protease of a fish retrovirus, walleye dermal sarcoma virus
| Autor: | Volker M. Vogt, Sharon K. Fodor |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Walleye epidermal hyperplasia virus
Epsilonretrovirus medicine.medical_treatment viruses Immunology Molecular Sequence Data Biology Microbiology Virus Retrovirus Virology Endopeptidases medicine Animals Amino Acid Sequence Cloning Molecular Protein Precursors Peptide sequence Polyproteins Protease Structure and Assembly Group-specific antigen biology.organism_classification Molecular biology Reverse transcriptase Recombinant Proteins Insect Science |
| Zdroj: | Journal of virology. 76(9) |
| ISSN: | 0022-538X |
| Popis: | Three fish retroviruses infecting walleyes constitute the recently recognized genus called epsilonretrovirus. The founding member of this group, walleye dermal sarcoma virus (WDSV), induces benign skin tumors in the infected fish and replicates near 4°C. While the viral genomic sequence is known, biochemical characterization of the virus has been limited to the identification of the mature structural and envelope proteins present in virions. We undertook this study to determine the cleavage sites in the WDSV Pro and Pol proteins and to characterize the viral protease (PR) in vitro. A recombinant PR was expressed in and purified from Escherichia coli as a larger fusion with additional nucleocapsid and reverse transcriptase residues flanking the PR domain. Autocleavage produced a functional, mature PR. Autocleavage as well as cleavage of peptides and of Gag protein by the mature PR occurred at a pH optimum of 7.0, higher than that of other retroviral proteases. Analysis of the cleavage sites identified a glutamine residue in the P2 position of all WDSV sites, both in Gag and in Pol. Amino acid sequence alignments of Gag-Pro-Pol from WDSV, walleye epidermal hyperplasia virus type 1, and walleye epidermal hyperplasia virus type 2 showed the P2 glutamine to be conserved in all cleavage sites in these three viruses. Such conservation is unprecedented in other retroviruses. |
| Databáze: | OpenAIRE |
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