Send to

Choose Destination
See comment in PubMed Commons below
Cell. 1984 Jul;37(3):1063-73.

Expression of a cloned gene segment of poliovirus in E. coli: evidence for autocatalytic production of the viral proteinase.


The poliovirus polyprotein is proteolytically processed predominantly by a virus-encoded proteinase (P3-7c) that cleaves glutamine-glycine amino acid pairs. The biosynthesis of the viral proteinase, itself a product of glutamine-glycine cleavages, was studied by constructing a bacterial expression plasmid that contained a cloned segment of the poliovirus genome slightly larger than the coding region for P3-7c. The induction of expression of this plasmid in E. coli produced several poliovirus-specific polypeptides. One polypeptide, an unstable protein called 3i, was the product of fortuitous in-phase initiation of translation within the coding region of P3-7c. Three other induced polypeptides were products of proteolytic cleavages, the smallest (polypeptide 3) having the properties (amino-terminal amino acids, carboxy-terminal amino acids, size, antigenicity) of P3-7c. Insertion of a DNA linker into the P3-7c coding region results in the loss of P3-7c-specific glutamine-glycine cleavage activity. We conclude that P3-7c was produced by autocatalytic cleavage.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center