title: Internal translation initiation and eIF4F/ATP-independent scanning of mRNA by eukaryotic ribosomal particles.
abstract: The recombinant mRNAs with 5'-untranslated region, called omega leader, of tobacco mosaic virus RNA are known to be well translated in eukaryotic cell-free systems, even if deprived of cap structure. Using the method of primer extension inhibition (toe-printing), the ribosomal particles were shown to initiate translation at uncapped omega leader when its 5'-end was blocked by a stable RNA-DNA double helix, thus providing evidence for internal initiation. The scanning of the leader sequence and the formation of ribosomal 48S initiation complexes at the initiation AUG codon occurred in the absence of ATP-dependent initiation factor eIF4F, as well as without ATP. The latter results implied the ability of ribosomal initiation complexes for ATP-independent, diffusional wandering (also called bi-directional movement) along the leader sequence during scanning.
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Sultan Ch
authors.initials: SCh
authors.lastname: Agalarov
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Pavel A
authors.initials: PA
authors.lastname: Sakharov
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Dina Kh
authors.initials: DKh
authors.lastname: Fattakhova
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Evgeny A
authors.initials: EA
authors.lastname: Sogorin
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Spirin
mesh_terms: D020121:5' Untranslated Regions; D000255:Adenosine Triphosphate / Q000235:genetics; D002474:Cell-Free System; D003062:Codon / Q000235:genetics; D056890:Eukaryota / Q000235:genetics; D039562:Eukaryotic Initiation Factor-4F / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D012270:Ribosomes / Q000235:genetics*; D014027:Tobacco Mosaic Virus / Q000235:genetics*
chemical_list: D020121:5' Untranslated Regions; D003062:Codon; D039562:Eukaryotic Initiation Factor-4F; D012333:RNA, Messenger; D000255:Adenosine Triphosphate