[Binding of the IRES of hepatitis C virus RNA to the 40S ribosomal subunit: role of protein p40].

Ribosomal protein p40 is a structural component of the 40S ribosomal subunit, which is partially homologuos to prokaryotic ribosomal protein S2 and has a long eukaryote-specific C-terminal region. In the present work, we have studied the binding of the Internal Ribosome Entry Site (IRES) of the hepatitis C virus (HCV) RNA to the 40S ribosomal subunit either deficient on protein p40, or saturated with the recombinant p40, or pre-bound to monoclonal antibodies (MAB) 4F6 against p40. It was shown that the apparent association constant of HCV IRES binding to 40S subunits directly depends on p40 content in the subunits.

[Molecular environment of the IIId subdomain of the IRES element of hepatitits C virus RNA on the human 40S ribosomal subunit].

The molecular environment of the key subdomain IIId of the internal ribosome entry site (IRES) element of hepatitis C virus (HCV) RNA in the binary complex with the human 40S ribosomal subunit was studied. To this end, HCV IRES derivatives bearing perfluorophenylazido groups activatable by mild UV at nucleotide G263 or A275 in the subdomain IIId stem were used. They were prepared by the complementarily addressed modification of the corresponding RNA transcript with alkylating oligodeoxynucleotide derivatives.

[Efficient cap-dependent in vitro and in vivo translation of mammalian mRNAs with long and highly structured 5'-untranslated regions].

According to generally accepted scanning model proposed by M. Kozak, the secondary structure of 5'-untranslated regions (5'-UTR) of eukaryotic mRNAs can only cause an inhibitory effect on the translation initiation since it would counteract migration of the 40S ribosomal subunit along the mRNA polynucleotide chain. Thus, the existence of efficiently translatable mRNAs with long and highly structured 5'-UTRs is not compatible with the cap-dependent scanning mechanism.

[Similar features in mechanisms of translation initiation of mRNAs in eukaryotic and prokaryotic systems].

Using as examples non-canonical features of translation initiation for some bacterial and mammalian mRNAs with unusual 5'- untranslated regions (5'-UTR) or lacking these regions (leaderless mRNAs), the authors of this review discuss similarities in mechanisms of translation initiation on prokaryotic and eukaryotic ribosomes.

[Molecular environment of the subdomain IIIe loop of the RNA IRES element of hepatitis C virus on the human 40S ribosomal subunit].

The molecular environment of the internal ribosome entry site (IRES) element of hepatitis C viral (HCV) RNA in the binary complex with the human 40S ribosomal subunit was studied. To this end, RNA derivatives bearing mild UV-reactive perfluorophenylazide groups at nucleotide G87 in IRES domain II and at nucleotide A296 in the subdomain IIIe loop were used, which were prepared by the RNA complementarily-addressed modification with alkylating oligonucleotide derivatives. None of the RNA derivatives were shown to be crosslinked to the 18S rRNA of the 40S subunit.