title: Translation elongation after assembly of ribosomes on the Cricket paralysis virus internal ribosomal entry site without initiation factors or initiator tRNA.
abstract: Reconstitution of translation elongation from purified components confirmed that ribosomes that assembled on the Cricket paralysis virus intercistronic internal ribosomal entry site (IRES) without the involvement of initiation factors or initiator tRNA were active in elongation and are, therefore, true initiation complexes. The first elongation cycle occurred without peptide bond formation on 80S ribosomes that did not contain tRNA in the P site. It required elongation factors 1A and 2 and A site-cognate aminoacylated tRNA. Cycloheximide arrested ribosomes on the IRES only after two cycles of elongation, when the first deacylated tRNA reached the E-site after translocation from the A-site.
authors.affiliation: Department of Microbiology, State University of New York Downstate Medical Center, Brooklyn, New York 11203, USA. tatyana.pestova@downstate.edu
authors.forename: Tatyana V
authors.initials: TV
authors.lastname: Pestova
authors.forename: Christopher U T
authors.initials: CU
authors.lastname: Hellen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003513:Cycloheximide / Q000494:pharmacology; D006135:Gryllidae / Q000821:virology; D066298:In Vitro Techniques; D007304:Insect Viruses / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010441:Peptide Chain Elongation, Translational / Q000187:drug effects; D010445:Peptide Elongation Factors / Q000235:genetics / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012358:RNA, Transfer, Met / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism
chemical_list: D010445:Peptide Elongation Factors; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D012358:RNA, Transfer, Met; D012367:RNA, Viral; D003513:Cycloheximide