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Picornaviral processing: Some new ideas
Author(s) -
Palmenberg Ann C.
Publication year - 1987
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240330306
Subject(s) - cleavage (geology) , chemistry , rna , ribosome , poliovirus , autocatalysis , biochemistry , protease , peptide , rna processing , microbiology and biotechnology , enzyme , biology , virology , virus , catalysis , paleontology , fracture (geology) , gene
Abstract Mature picornaviral proteins are derived by progressive, post‐translational cleavage of a giant precursor polyprotein. At least three viral‐encoded proteolytic activities are involved in the processing. The first cleavage takes place while the polyprotein is still nascent on a ribosome. In poliovirus, this event is probably catalyzed by peptide 2A, a protein from the middle portion of the genome. Most subsequent processing is effected by viral protease 3C, a thiol‐type enzyme, responsible for eight to ten self‐cleaving and autocatalytic reactions within the polyprotein. The final proteolytic processing event, maturation of the VPO peptide, may occur by a novel, autocatalytic, serine‐type mechanism, where viral RNA serves as proton‐acceptor during the cleavage reaction.