文章基本信息

标题：Protein Initiation in Eukaryotes: Formation and Function of a Ternary Complex Composed of a Partially Purified Ribosomal Factor, Methionyl Transfer RNAf, and Guanosine Triphosphate
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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：1973
卷号：70
期号：1
页码：41-45
DOI：10.1073/pnas.70.1.41
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A protein factor contained in a 1 M KCl extract of L-cell ribosomes and partially purified by chromatography on DEAE-cellulose forms a specific ternary complex with rat-liver Met-tRNAf and GTP. The complex is measured by its quantitative retention on nitrocellulose membranes. Complex assembly is optimal at 100 mM KCl and 0.2 mM MgCl2, and is independent of mRNA and of ribosomes. The GTP requirement can be replaced over 65% by its methylene analogue GDPCH2P, indicating that GTP hydrolysis is not involved. Complex formation is inhibited by 10 {micro}M aurintricarboxylic acid, but is unaffected by 100 {micro}M pactamycin, 100 {micro}M fusidic acid, or by excess uncharged methionine tRNAf. The ternary complex is relatively stable and appears at the void volume during filtration on Sephadex G-100. At 1-3 mM MgCl2 and in the presence of other factors, the ternary complex is implicated in protein initiation by (i) its capacity to bind to the 40S ribosomal subunit to form a 48S complex; and (ii) the subsequent association of the 48S complex with a 60S subunit to form a functional "80S complex."
关键词：binding assay ; L-cells ; ribosome subunits ; protein inhibitors