文章基本信息

标题：Formation of a Mammalian Initiation Complex with Reovirus Messenger RNA, Methionyl-tRNAF, and Ribosomal Subunits
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作者：Daniel H. Levin ; David Kyner ; George Acs 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1972
卷号：69
期号：5
页码：1234-1238
DOI：10.1073/pnas.69.5.1234
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Previous data demonstrated that reovirus mRNA, synthesized in vitro with the particulate RNA transcriptase of reovirus cores, efficiently directs the synthesis of polypeptides in vitro. The present studies indicate that all of the three size classes of reovirus mRNA produced in vitro can form protein initiation complexes with rat liver [36S]Met-tRNAF and incubated 40S and 60S ribosomal subunits, which had been washed in 0.5 M KCl of mouse fibroblast L-929 cells. Mild prior treatment of the mRNA with HCHO was required to expose the initiator region. The initiation complex reacted quantitatively with puromycin to form a puromycin peptide, whose electrophoretic properties were identical to methionyl-puromycin formed in response to poly(A,G,U) or the initiator codon AUG. The complex was relatively stable and specific for [35S]Met-tRNAF; rat liver [35S]Met-tRNAM was unreactive unless the supernatant factors EF T1 and EF T2 were also present. However, the addition of fusidic acid, at a concentration that did not affect complex formation with [35S]Met-tRNAF, completely inhibited Met-tRNAM utilization. Exogenous ribosomal factors and GTP were not required unless the separated 40S and 60S subunits were further treated with 1 M KCl. The data suggest that reovirus mRNA contains AUG initiator codons that form a complex with Met-tRNAF at a puromycin-reactive site on ribosomes.
关键词：protein initiation ; binding ; puromycin peptides ; Met-tRNA_M