19 Initiation of Translation by Picornavirus RNAs

摘要: About 15 years ago, soon after the initial development of methods to apply recombinant DNA and powerful sequencing technology RNA molecules, complete sequence poliovirus was determined (Kitamura et al. 1981; Racaniello Baltimore 1981). It immediately apparent that primary structure 5′ end viral inconsistent with cap-dependent scanning model for translation initiation so successfully being developed presented most cellular messenger RNAs (Kozak 1978Kozak 1989). There a striking absence an m 7 G cap on terminus RNA, initiating AUG codon located at position 743 nucleotides downstream from end. The resulting long 5′-untranslated region (5′ UTR) contained numerous unused triplets as well complex predicted secondary would present significant obstacles ribosome. Evidence alternate ribosome-binding mechanism accumulated slowly, until another related encephalomyocarditis virus (EMCV) became first demonstrated examples cap-independent internal (Jang 1988; Pelletier Sonenberg 1988). sequences structures within UTR required are known ribosome entry site (IRES). rationale evolving unique binding in case these rapidly growing, lytic viruses might appear be enable interfere translation, thereby eliminating competition essential components, more...