Physical and molecular genetic analysis of the multistep proteolytic maturation pathway utilized by vaccinia virus P4a protein
| Autor: | Neil A. Bersani, Dennis E. Hruby, Stephen S. Whitehead |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Proteolysis
Recombinant Fusion Proteins Molecular Sequence Data Peptide Vaccinia virus Biology Cleavage (embryo) Peptide Mapping Virus chemistry.chemical_compound Virology medicine Coding region Amino Acid Sequence Protein Precursors chemistry.chemical_classification medicine.diagnostic_test Viral Core Proteins Molecular biology Fusion protein Peptide Fragments Molecular analysis Molecular Weight chemistry Biochemistry Mutation Vaccinia Protein Processing Post-Translational Sequence Analysis |
| Zdroj: | The Journal of general virology. 76 |
| ISSN: | 0022-1317 |
| Popis: | Three potential AG*X cleavage sites have previously been identified in vaccinia virus (VV) P4a precursor, namely AG*N, AG*S and AG*T. Utilization of the COOH-proximal AG*T site in P4a leads to release of a 23 kDa product (‘23K’). Here we propose that cleavage at the AG*S site alone is responsible for release of 4a, based on peptide mapping and microsequencing which demonstrated that the NH2 terminus of 4a is co-terminal with P4a, thus indicating that the AG*N site is excluded from proteolytic processing. Proteolysis of P4a at AG*S and AG*T to yield 4a and 23K should theoretically also liberate an intervening 9 kDa peptide (‘9K’), although efforts to isolate this peptide have been repeatedly unsuccessful. To investigate the fate of this intervening peptide, mutation of the P4a coding sequence at the AG*S or AG*T site, followed by transient expression in VV-infected cells, lead to the synthesis of unique 4a-9K or 9K–23K chimeric protein products. This implies that neither end of the intervening 9K peptide is intrinsically destabilizing, and that its supposed degradation may be suppressed when it remains associated with 4a or 23K. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|