Chimeric picornavirus polyproteins demonstrate a common 3C proteinase substrate specificity.

AUTOR(ES)

Dewalt, P G

RESUMO

Cross-species proteolytic processing was demonstrated by the 3C proteinases of human rhinovirus 14 and coxsackievirus B3 on poliovirus-specific polypeptide precursors. Chimeric picornavirus cDNA genomes were constructed in a T7 transcription vector in which the poliovirus 3C coding region was substituted with the corresponding allele from human rhinovirus 14 or coxsackievirus B3. In vitro translation and processing of the polypeptides encoded by the chimeric genomes demonstrated that the proteolytic processing of poliovirus P2 region (nonstructural) proteins could be functionally substituted by the heterologous proteinases. In contrast, the 3C proteinase activities expressed from the chimeric genomes were incapable of recognizing the poliovirus-specific processing sites within the capsid precursor. Since the amino acid sequences flanking and inclusive of the P2 region cleavage sites of the three viruses are not stringently conserved, these results provide evidence for the existence of common conformational determinants necessary for 3C-mediated processing.

Documentos Relacionados

• A rapid method for determination of endoproteinase substrate specificity: specificity of the 3C proteinase from hepatitis A virus.
• Cleavage specificity of purified recombinant hepatitis A virus 3C proteinase on natural substrates.
• GB virus B and hepatitis C virus NS3 serine proteases share substrate specificity.
• A 5'----3' exoribonuclease of human placental nuclei: purification and substrate specificity.
• Poliovirus thiol proteinase 3C can utilize a serine nucleophile within the putative catalytic triad.