文章基本信息

标题：Kirromycin, an Inhibitor of Protein Biosynthesis that Acts on Elongation Factor Tu
本地全文：下载
作者：Heinz Wolf ; Gianni Chinali ; Andrea Parmeggiani 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：1974
卷号：71
期号：12
页码：4910-4914
DOI：10.1073/pnas.71.12.4910
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Kirromycin, a new inhibitor of protein synthesis, is shown to interfere with the peptide transfer reaction by acting on elongation factor Tu (EF-Tu). All the reactions associated with this elongation factor are affected. Formation of the EF-Tu{middle dot}GTP complex is strongly stimulated. Peptide bond formation is prevented only when Phe-tRNAPhe is bound enzymatically to ribosomes, presumably because GTP hydrolysis associated with enzymatic binding of Phe-tRNAPhe is not followed by release of EF-Tu{middle dot}GDP from the ribosome. This antibiotic also enables EF-Tu to catalyze the binding of Phe-tRNAPhe to the poly(U){middle dot}ribosome complex even in the absence of GTP. EF-Tu activity in the GTPase reaction is dramatically affected by kirromycin: GTP hydrolysis, which normally requires ribosomes and aminoacyl-tRNA, takes place with the elongation factor alone. This GTPase shows the same Km for GTP as the one dependent on Phe-tRNAPhe and ribosomes in the absence of the antibiotic. Ribosomes and Phe-tRNAPhe, but not tRNAPhe or Ac-Phe-tRNAPhe, stimulate the kirromycin-induced EF-Tu GTPase. These results indicate that the catalytic center of EF-Tu GTPase that is dependent upon aminoacyl-tRNA and ribosomes is primarily located on the elongation factor. In conclusion, kirromycin can substitute for GTP, aminoacyl-tRNA, or ribosomes in various reactions involving EF-Tu, apparently by affecting the allosteric controls between the sites on the EF-Tu molecule interacting with these components.
关键词：EF-Tu GTPase ; peptide bond formation ; aminoacyl-tRNA binding ; ribosomal complexes